6th Grade- Chapter 1 Online Study

6th Grade - CH 1 ONLINE STUDY

True/False
Indicate whether the statement is true or false.

____ 1. A scientific law is an explanation of things or events based on observations.

____ 2. The theory that living things come only from other living things is called biogenesis.

____ 3. A theory is the same as a hypothesis.

____ 4. Pasteur showed that living things do not come from nonliving materials.

____ 5. All the changes that organisms undergo as they grow are called growth.

____ 6. Spontaneous generation is the evolutionary history of an organism.

____ 7. A variable is the factor that is tested in an experiment.

____ 8. A stimulus causes a change or response in an organism.

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____ 9. What is NOT a way that scientists would use to solve problems?
a.
analyze data
b.
ask questions
c.
make guesses
d.
perform experiments


____ 10. Anthony wants to see if plant food would make his roses grow better. On one side of the garden, he uses plant food. On the other side, he does not use plant food. What is the variable in his experiment?
a.
the brand of plant food used
b.
the type of soil used to grow the roses
c.
which roses receive plant food
d.
what type of roses the gardener grows


____ 11. What evidence do scientists use to form conclusions about their experiments?
a.
data and observations
b.
newspaper articles
c.
old scientific theories
d.
people’s opinions


____ 12. What is a scientific theory?
a.
An explanation of things or events based on opinion.
b.
An explanation of things or events based on estimated guesses.
c.
An explanation of things or events based on a rejected hypothesis.
d.
An explanation of things or events based on knowledge.


____ 13. What is the best explanation of a scientific law?
a.
A statement about how things work in nature that seems to be true some of the time.
b.
A statement about how things work in nature that seems to be true all of the time.
c.
A statement about how things work in nature that needs to be proved with further experiments.
d.
A statement about how things work in nature that seems to be based on many opinions.


____ 14. This chart shows part of the international system of units. Amy buys a candy bar. On the candy’s wrapper it says “39 g.”
According to the chart, what does 39 g measure?
a.
liter
b.
kilogram
c.
mass
d.
volume


____ 15. What term is used to describe any living thing?
a.
biogenesis
b.
cell
c.
organism
d.
reproduction


____ 16. Who hypothesized that ammonia, hydrogen, methane, and water vapor in Earth’s early atmosphere could have combined to form the more complex compounds found in living things?
a.
Stanley Miller
b.
John Needham
c.
Alexander Oparin
d.
Louis Pasteur


____ 17. Lee is studying Antarctica. She makes this chart about the king penguin, one of the animals that lives in this harsh environment.
What does the genus of the king penguin tell her?
a.
Genus tells who discovered the animal.
b.
Genus explains the location the animal was discovered.
c.
Genus is a group of similar species.
d.
Genus describes what kind of food the penguin eats.


____ 18. Which scientist developed a new system of grouping organisms in the late eighteenth century?
a.
Sir Isaac Newton
b.
Carolus Linnaeus
c.
Louis Pasteur
d.
Harold Urey


____ 19. When an animal is hungry, it eats food. When it is thirsty, it drinks water. When it is cold, it seeks a warmer temperature. Which trait displayed by all living things do these examples represent?
a.
biogenesis
b.
classification
c.
homeostasis
d.
variable


____ 20. Marina reads that polar bears rely on polynyas for survival. Polynyas are areas of ocean surrounded by ice that remain open throughout the year. This ice-free water is rich in plant and animal life. Polar bears live on the surrounding ice and use sea ice platforms to hunt seals. Marina learns that polar bears require what basic needs for survival?
a.
a place to live and raw materials
b.
ice on land where they can live
c.
large ice platforms in the sea
d.
sea water rich in plants and animals


____ 21. Sylvia imagines that she is a scientist living in the eighteenth century. She observes many earthworms on the ground after a rain storm. She concludes that the earthworms must have fallen from the sky during the storm. On what scientific theory is she basing her conclusion?
a.
biogenesis
b.
Miller’s Theory
c.
Oparin’s Hypothesis
d.
spontaneous generation


____ 22. What type of field guide would be the easiest and most efficient to use?
a.
encyclopedia with phylum names only
b.
dichotomous key
c.
Aristotle system
d.
encyclopedia with species names only


____ 23. Which is NOT a function of a dichotomous key?
a.
avoid errors in communication
b.
organisms with similar evolutionary histories are classified together
c.
give descriptive information
d.
more difficult to find and identify species


____ 24. The first name of the organism's scientific name is the ____.
a.
species
c.
genus
b.
family
d.
order


____ 25. Scientific names of organisms consist of ____.
a.
genus and specific name
c.
family and genus
b.
order and family
d.
class and order


____ 26. The classification system most commonly used today separates organisms into ____ kingdoms.
a.
three
c.
five
b.
four
d.
six


____ 27. Of the following, which would NOT be grouped with the others?
a.
blue jeans
c.
sweat pants
b.
shorts
d.
sweatshirt


____ 28. Dichotomous keys are divided into steps with ____ descriptions at each step.
a.
two
c.
five
b.
three
d.
four


____ 29. Linnaeus's system gave how many names to each organism?
a.
two
c.
one
b.
three
d.
four


____ 30. If you know an insect is a butterfly but don't know its scientific name, it would be best to use a(n) ____ to find out.
a.
dictionary
c.
biology textbook
b.
encyclopedia
d.
dichotomous key


____ 31. The theory that living things come only from other living things is called ____.
a.
adaptation
c.
spontaneous generation
b.
biogenesis
d.
homeostasis


____ 32. The belief that living things come from nonliving things is called ____.
a.
biogenesis
c.
homeostasis
b.
respiration
d.
spontaneous generation


____ 33. To solve a problem, scientists follow a series of steps called ____.
a.
a dichotomous key
c.
classifications
b.
scientific methods
d.
Systems or Units


____ 34. Growth of many-celled organisms is mostly due to an increase in the ____ of cells.
a.
size
c.
number
b.
protons
d.
all of the above


____ 35. Babies laughing at four months is an example of ____.
a.
adaptation
c.
growth
b.
development
d.
respiration


____ 36. An organism’s ability to maintain a steady condition is called ____.
a.
biogenesis
c.
osmosis
b.
homeostasis
d.
respiration


____ 37. Linnaeus’s major contribution to organism classification was ____.
a.
a six-kingdom system
c.
grouping kingdoms and phylums
b.
binomial nomenclature
d.
grouping by class, order, and family


____ 38. The first word of an organism’s scientific name is the ____.
a.
class
c.
kingdom
b.
genus
d.
species


____ 39. Most living things are made up of more than ____ percent water.
a.
80
c.
60
b.
50
d.
70


____ 40. The idea that living things come from nonliving things is called ____.
a.
adaptation
c.
homeostasis
b.
biogenesis
d.
spontaneous generation


____ 41. The doctor who showed that maggots hatch from eggs that flies lay on meat, and not from the meat itself, was ____.
a.
Pasteur
c.
Spallanzani
b.
Redi
d.
van Helmont


____ 42. In the late 1700s, ____ designed an experiment to show that tiny organisms come from other tiny organisms in the air.
a.
Miller
c.
Redi
b.
Oparin
d.
Spallanzani


____ 43. The theory that living things come only from living things is called ____.
a.
biogenesis
c.
ecology
b.
development
d.
spontaneous generation


____ 44. A detailed list of identifying characteristics that includes scientific names is called a ____.
a.
domain
c.
field guide
b.
dichotomous key
d.
phylum


____ 45. ____ experiment showed that substances present in living things could be made from nonliving things in the environment.
a.
Miller’s
c.
Redi’s
b.
Pasteur’s
d.
Van Helmont’s


____ 46. A ____ is a prediction that can be tested.
a.
hypothesis
c.
theory
b.
scientific law
d.
variable


____ 47. A(n) ____ is an explanation of things or events based on many observations.
a.
control
c.
hypothesis
b.
experiment
d.
theory


____ 48. The SI unit of mass is the ____.
a.
cubic meter
c.
liter
b.
kilogram
d.
meter


____ 49. All of the following EXCEPT ____ are SI units.
a.
kilometer
c.
gram
b.
inch
d.
tonne


Completion
Complete each statement.

50. The theory that living things come only from other living things is known as ____________________.

51. A two-word name used to classify living things is ______________________________.

52. Anything an organism responds to is a(n) ____________________.

53. The ability to remain stable is called ____________________.

54. The smallest units of life are known as ____________________.

55. Another term for living things is ____________________.

56. The reaction of an organism to a stimulus is called a ____________________.

57. The ____________________ of an organism is its evolutionary history.

58. The ____________________ in an experiment is the standard used to compare with the outcome.

Unscramble the letters to form the correct word for each definition.

59. smirsogna—living things ____________________

60. clesl—smallest units carrying on life functions ____________________

61. nobimali nmclaoenture—naming system developed by Linnaeus _________________________

62. gomnikd—the first and largest category in the classification used today ____________________

63. wal—a statement about how things work in nature ____________________

64. shamestoiso—ability to maintain a steady condition ____________________

65. ynyhpolge—history of how an organism has changed over time ____________________

66. snuge—groups of similar species ____________________

67. stenopausno reonigtean—the idea that living things come from nonliving things _________________________

68. snibgiesoe—idea that living things come only from other living things ____________________

69. ceitsniicf demstoh—organized steps to solve a problem ____________________

70. spetysohih—prediction that can be tested ____________________

71. bavelria —what is being tested in an experiment ____________________

72. lortnoc—standard used to compare the test materials ____________________

73. royeht—an explanation based on many observations ____________________

Complete the following sentences using the terms listed below. Some terms may not be used.

law
critical thinking
measurement
botany
volume
experiment


74. ____________________ is a process that uses certain skills to solve problems.

75. A scientific ____________________ is a rule that tells us how nature works.

76. The International System of Units (SI) is a system of ____________________.

77. To measure the ____________________ of a small amount of liquid, you might use a graduated cylinder.

78. Scientists often perform a(n) ____________________ to test a hypothesis under controlled conditions.

79. People once believed that living things came from nonliving matter, an idea called _________________________.

80. Redi’s experiment showed that ____________________ hatch from eggs of flies, not from meat.

81. An experiment by Pasteur showed that living things do not come from ____________________ things.

82. The theory of ____________________ replaced the theory of spontaneous generation.

83. Oparin’s hypothesis suggested that early Earth’s atmosphere lacked ____________________.

84. Miller and Urey showed that substances in ____________________ things could be made from nonliving things in the environment.

Matching

Match each item with the correct description. Some items may not be used.
a.
adaptation
h.
organism
b.
biogenesis
i.
response
c.
cell
j.
scientific methods
d.
control
k.
stimulus
e.
development
l.
theory
f.
homeostasis
m.
variable
g.
life span



____ 85. living thing

____ 86. smallest unit of organisms that carries on life functions

____ 87. changes that living things undergo as they grow

____ 88. anything an organism reacts to

____ 89. reaction of an organism to a stimulus

____ 90. characteristic of an organism that helps it to survive in its environment

____ 91. organized problem-solving procedure in science

____ 92. what is being tested in an experiment

____ 93. standard to which the outcome of a test is compared

____ 94. the maintenance of steady conditions inside an organism

Short Answer

95.
Explain the difference between spontaneous generation and biogenesis.

96.
What are the needs of living things?

97.
Where do organisms get energy?

98.
What is a hypothesis?

99.
What is a variable?

100.
What do the trees Tsuga canadensis and Tsuga caroliniana have in common?

101.
Which of Aristotle's concepts are still in use in classification systems today?

102.
You are an American scientist working with Chinese scientists to protect the endangered giant panda. As you can't speak or write Chinese, how do you make sure that your coworkers and you are working on the same animal?

103.
Why do organisms need food?

104.
What is Linnaeus's most important contribution to biology?

105.
Oparin suggested that the atmosphere of early Earth was made up of what gases?

106.
What are cells?

107.
Why is water essential to living things?

108.
Why did people believe that rain brought earthworms?

109.
What term refers to the length of time an organism is expected to live?

110.
What SI unit measures how much juice is in a bottle?

111.
Explain how results that show a hypothesis to be wrong are just as important as results that show a hypothesis to be correct.

112.
How can you tell whether a rock is a living thing?

113.
Group the items listed into two groups and explain why they are grouped that way: bats, fish, eagles, dolphins, butterflies, tadpoles, sparrows, water snakes.

114.
What are the four basic functions that scientific names serve?

115.
Choose an animal that you are familiar with, such as a dog or a cat, and list characteristics you could use to identify the animal in a dichotomous key.

116.
List the five features that describe living things.

117. List the units a scientist would probably use to measure the following examples.
a. length of a room
b. large distances
c. weight of a bag of flour
d. weight of a pencil
e. temperature of a sick child
f. volume of milk

118. Describe the characteristics of living things.

119. How do living and nonliving things interact in the environment?

Answer the following questions using the scientific names for trees listed below.

Pinus banksiana
Pinus contorta
Pinus resinosa
Pinus virginiana


120. What do the trees have in common?

121. What can you infer is the common name for this type of tree?

122. Where might you expect to find Pinus virginiana in abundance?

123. Using the dichotomous key, identify the following species.



Dichotomous Key to Animal Tracks
1.
a.
toe print separate from sole print, go to 2

b.
toe print attached to sole print, go to 3
2.
a.
toes with long claws, Mephitis mephitis (skunk)

b.
toes with short claws, Mustela vison (mink)
3.
a.
regular-shaped toes, go to 4

b.
irregular-shaped toes, Didelphis virginiana (opossum)
4.
a.
hind toes webbed, Castor canadensis (beaver)

b.
hind toes not webbed, Marmota monax (woodchuck)


124. List five characteristics of living things.

125. List the steps usually followed in scientific methods.

Essay

126.
Explain Oparin’s Hypothesis. Was it ever tested by other scientists?

127. Explain how Pasteur’s experiments showed that living things do not come from nonliving things.

128. Summarize Oparin’s hypothesis and how it was tested.
6th Grade - CH 1 ONLINE STUDY
Answer Section

TRUE/FALSE

1. ANS: F PTS: 1 DIF: Webb's I OBJ: 1/1

2. ANS: T PTS: 1 DIF: Webb's I OBJ: 6/3

3. ANS: F PTS: 1 DIF: Webb's I OBJ: 1/1

4. ANS: T PTS: 1 DIF: Webb's I OBJ: 6/3
STA: SC.H.3.3.5

5. ANS: F PTS: 1 DIF: Webb's I OBJ: 3/2
STA: SC.F.1.3.1

6. ANS: F PTS: 1 DIF: Webb's I OBJ: 5/3

7. ANS: T PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.H.1.3.5

8. ANS: T PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.H.1.3.5

MULTIPLE CHOICE

9. ANS: C PTS: 1 DIF: Webb's I STA: SC.H.1.3.4

10. ANS: C PTS: 1 DIF: Webb's II STA: SC.H.1.3.2 SC.H.1.3.5

11. ANS: A PTS: 1 DIF: Webb's I STA: SC.H.1.3.4

12. ANS: D PTS: 1 DIF: Webb's I STA: SC.H.1.3.1 SC.H.3.3.6

13. ANS: B PTS: 1 DIF: Webb's I
STA: SC.H.1.3.1 SC.H.2.3.1 SC.H.3.3.6

14. ANS: C PTS: 1 DIF: Webb's II

15. ANS: C PTS: 1 DIF: Webb's I STA: SC.G.1.3.3

16. ANS: C PTS: 1 DIF: Webb's I
STA: SC.G.1.3.4 SC.H.1.3.6 SC.H.3.3.5

17. ANS: C PTS: 1 DIF: Webb's II STA: SC.G.1.3.3

18. ANS: B PTS: 1 DIF: Webb's I STA: SC.G.1.3.3 SC.H.3.3.5

19. ANS: C PTS: 1 DIF: Webb's II STA: SC.G.1.3.4

20. ANS: A PTS: 1 DIF: Webb's II STA: SC.G.1.3.4

21. ANS: D PTS: 1 DIF: Webb's II STA: SC.H.1.3.1

22. ANS: B PTS: 1 DIF: Webb's I OBJ: 10/4
STA: SC.H.1.3.4 SC.H.1.3.5

23. ANS: D PTS: 1 DIF: Webb's II OBJ: 10/4
STA: SC.H.1.3.4 SC.H.1.3.5

24. ANS: C PTS: 1 DIF: Webb's I OBJ: 9/4
STA: SC.G.1.3.3

25. ANS: A PTS: 1 DIF: Webb's I OBJ: 9/4
STA: SC.G.1.3.3

26. ANS: D PTS: 1 DIF: Webb's I OBJ: 9/4
STA: SC.G.1.3.3 SC.H.1.3.5

27. ANS: D PTS: 1 DIF: Webb's I OBJ: 8/4
STA: SC.G.1.3.3 SC.H.1.3.5

28. ANS: A PTS: 1 DIF: Webb's I OBJ: 10/4
STA: SC.H.1.3.4

29. ANS: A PTS: 1 DIF: Webb's I OBJ: 8/4
STA: SC.H.1.3.4 SC.G.1.3.3

30. ANS: D PTS: 1 DIF: Webb's I OBJ: 10/4
STA: SC.H.1.3.4

31. ANS: B PTS: 1 DIF: Webb's I OBJ: 6/3

32. ANS: D PTS: 1 DIF: Webb's I OBJ: 5/3

33. ANS: B PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.H.1.3.4

34. ANS: C PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.F.1.3.1

35. ANS: B PTS: 1

36. ANS: B PTS: 1

37. ANS: B PTS: 1

38. ANS: B PTS: 1

39. ANS: B PTS: 1

40. ANS: D PTS: 1

41. ANS: B PTS: 1

42. ANS: D PTS: 1

43. ANS: A PTS: 1

44. ANS: B PTS: 1

45. ANS: A PTS: 1

46. ANS: A PTS: 1

47. ANS: D PTS: 1

48. ANS: B PTS: 1

49. ANS: B PTS: 1

COMPLETION

50. ANS: biogenesis

PTS: 1 DIF: Webb's I OBJ: 6/3

51. ANS: binomial nomenclature

PTS: 1 DIF: Webb's I OBJ: 9/4 STA: SC.G.1.3.3

52. ANS: stimulus

PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.F.1.3.7

53. ANS: homeostasis

PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.F.1.3.1

54. ANS: cells

PTS: 1 DIF: Webb's I OBJ: 3/2 STA: SC.F.1.3.1

55. ANS: organisms

PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.G.1.3.3

56. ANS: response

PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.F.1.3.7

57. ANS: phylogeny

PTS: 1 DIF: Webb's I OBJ: 8/4 STA: SC.G.1.3.3

58. ANS: control

PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.H.1.3.5

59. ANS: organisms

PTS: 1

60. ANS: cells

PTS: 1

61. ANS: binomial nomenclature

PTS: 1

62. ANS: kingdom

PTS: 1

63. ANS: law

PTS: 1

64. ANS: homeostasis

PTS: 1

65. ANS: phylogeny

PTS: 1

66. ANS: genus

PTS: 1

67. ANS: spontaneous generation

PTS: 1

68. ANS: biogenesis

PTS: 1

69. ANS: scientific methods

PTS: 1

70. ANS: hypothesis

PTS: 1

71. ANS: variable

PTS: 1

72. ANS: control

PTS: 1

73. ANS: theory

PTS: 1

74. ANS: Critical thinking

PTS: 1

75. ANS: law

PTS: 1

76. ANS: measurement

PTS: 1

77. ANS: volume

PTS: 1

78. ANS: experiment

PTS: 1

79. ANS: spontaneous generation

PTS: 1

80. ANS: maggots

PTS: 1

81. ANS: nonliving

PTS: 1

82. ANS: biogenesis

PTS: 1

83. ANS: oxygen

PTS: 1

84. ANS: living

PTS: 1

MATCHING

85. ANS: H PTS: 1

86. ANS: C PTS: 1

87. ANS: E PTS: 1

88. ANS: K PTS: 1

89. ANS: I PTS: 1

90. ANS: A PTS: 1

91. ANS: J PTS: 1

92. ANS: M PTS: 1

93. ANS: D PTS: 1

94. ANS: F PTS: 1

SHORT ANSWER

95. ANS:
Spontaneous generation is the idea that living things come from non-living things. It was a popular theory from the late seventeenth century through the middle of the eighteenth century. Biogenesis is the theory that living things come only from preexisting life.

PTS: 1 DIF: Webb's II STA: SC.G.1.3.4 SC.H.1.3.1

96. ANS:
energy and raw materials

PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.G.1.3.4 SC.G.1.3.5

97. ANS:
from food

PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.G.1.3.4

98. ANS:
a prediction that can be tested

PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.H.1.3.1

99. ANS:
the factor tested in an experiment

PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.H.1.3.5

100. ANS:
Both belong to the genus Tsuga.

PTS: 1 DIF: Webb's II OBJ: 9/4 STA: SC.G.1.3.3

101. ANS:
grouping organisms into large groups, then dividing them into smaller subgroups

PTS: 1 DIF: Webb's II OBJ: 8/4 STA: SC.G.1.3.3

102. ANS:
You use the giant panda's scientific name.

PTS: 1 DIF: Webb's II OBJ: 9/4 STA: SC.G.1.3.3

103. ANS:
Organisms need food to provide energy for life activities such as growth and reproduction.

PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.G.1.3.4

104. ANS:
the development of binomial nomenclature as a method for identifying species worldwide

PTS: 1 DIF: Webb's II OBJ: 8/4
STA: SC.G.1.3.3 SC.H.1.3.6 SC.H.3.3.5

105. ANS:
Oparin suggested that the atmosphere was made up of gases similar to ammonia, hydrogen, methane, and water vapor.

PTS: 1 DIF: Webb's II OBJ: 6/3 STA: SC.H.1.3.6 SC.H.3.3.5

106. ANS:
the smallest units of organisms that carry on the functions of life

PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.F.1.3.5

107. ANS:
Living things are made up of more than 50 percent water and must maintain that level.

PTS: 1 DIF: Webb's II OBJ: 4/2 STA: SC.G.1.3.4

108. ANS:
Earthworms always appeared in large numbers after rainstorms.

PTS: 1 DIF: Webb's I OBJ: 5/3 STA: SC.H.1.3.1

109. ANS:
life span

PTS: 1 DIF: Webb's II OBJ: 3/2

110. ANS:
the liter or milliliter

PTS: 1 DIF: Webb's I OBJ: 2/1

111. ANS:
Results that show a hypothesis to be wrong help scientists choose a better hypothesis to test. This narrows the answers to be tested.

PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.H.1.3.1 SC.H.1.3.2

112. ANS:
Answers should include that living things must be made of cells, use energy, move, respond, adjust, reproduce, grow, develop, and require energy and water.

PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.F.1.3.1 SC.F.1.3.4 SC.G.1.3.3

113. ANS:
Group one would include bats, eagles, butterflies, sparrows—things that fly. Group two would include fish, dolphins, tadpoles, water snakes—things that swim.

PTS: 1 DIF: Webb's II OBJ: 8/4 STA: SC.G.1.3.3

114. ANS:
They avoid confusion among scientists, group organisms with similar evolutionary histories together, give information about the species, and allow information to be organized and retrieved efficiently.

PTS: 1 DIF: Webb's III OBJ: 9/4 STA: SC.G.1.3.3

115. ANS:
Answers will vary but should indicate teeth, claws, size, etc.

PTS: 1 DIF: Webb's III OBJ: 10/4 STA: SC.G.1.3.3

116. ANS:
Living things are organized into one or more cells, interact with their surroundings, use energy, grow and develop, and reproduce.

PTS: 1 DIF: Webb's II OBJ: 3/2 STA: SC.F.1.3.1 SC.F.1.3.4

117. ANS:
a. meter
b. kilometer
c. kilogram
d. gram
e. degree
f. liter

PTS: 1

118. ANS:
Living things are made up of one or more cells, use energy, move, respond to their environment, reproduce, grow, develop, adapt, and have a life span.

PTS: 1

119. ANS:
Nonliving things such as water, oxygen, and carbon dioxide are needed by living things to survive. These materials are returned to the environment and are used again.

PTS: 1

120. ANS:
They all belong to the genus Pinus.

PTS: 1

121. ANS:
They are pine trees.

PTS: 1

122. ANS:
It grows abundantly in the state of Virginia.

PTS: 1

123. ANS:
1. skunk
2. mink
3. beaver
4. opossum
5. woodchuck

PTS: 1

124. ANS:
Accept any five of the following (order will vary): They are made of one or more cells; they move; they respond to changes in their environment; they use energy; they reproduce; they grow and develop; they adapt; they have life spans.

PTS: 1

125. ANS:
1. State the problem.
2. Gather information about the problem.
3. Form a hypothesis.
4. Perform an experiment to test the hypothesis.
5. Analyze data.
6. Draw a Conclusion.
7. Report results.

PTS: 1

ESSAY

126. ANS:
In 1924, a Russian scientist named Alexander Oparin suggested that the Earth’s early atmosphere had no oxygen but was made up of the gases ammonia, hydrogen, methane, and water vapor. He hypothesized that these gases could have combined to form the more complex compounds found in living things. In 1953, Miller and Urey tested Oparin’s Hypothesis. They showed that chemicals found in living things could be produced, however, it did not prove that life began this way.

PTS: 1 DIF: Webb's II STA: SC.G.1.3.4 SC.H.3.3.5

127. ANS:
Broth became contaminated only when dust that had collected in the curved neck of one flask was allowed to mix with the broth. This showed that the contamination, or new organisms, did not come from the broth.

PTS: 1

128. ANS:
He suggested that the atmosphere of early Earth was made up of gases similar to ammonia, hydrogen, methane, and water vapor. No oxygen was present in the atmosphere as it is today. Energy from lightning, the Sun, and Earth’s heat triggered chemical reactions early in Earth’s history. The newly formed molecules washed into Earth’s ancient oceans and became a part of what is often called the primordial soup. Stanley Miller and Harold Urey sent electric currents through a mixture of gases like those thought to be in Earth’s early atmosphere. When the gases cooled, they condensed to form an oceanlike liquid that contained materials such as amino acids, found in present-day cells.

PTS: 1

7th Grade- Chapter 5 Online Review

7th Grade - CHpater 5 ONLINE REVIEW

True/False
Indicate whether the statement is true or false.

____ 1. When you perform work on an object you increase the energy of the object.

____ 2. A force at any angle to the direction of motion can perform work.

____ 3. Work is measured in joules.

____ 4. All forms of energy can do work.

____ 5. Under certain conditions, it is possible to get more work out of a machine than you put into it.

____ 6. Power is the rate at which a force is applied.

____ 7. The unit of power is the watt.

____ 8. Machines may allow you to do less work over a longer distance.

____ 9. The thread around a screw is a lever.

____ 10. The mechanical advantage of a wheel and axle is the radius of the wheel divided by the radius of the axle.

____ 11. A broom is an example of a wedge.

____ 12. Power and work are interchangeable terms.

____ 13. If you use a ramp that is 6 m long to move an object upward 1 m, then the mechanical advantage of the ramp is 6.

____ 14. You are doing NO work when you hold your 23-kg dog in your arms.

____ 15. You do 1 J of work if you use a force of 1 N for a distance of 1 m.

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____ 16. Which is NOT an example of a compound machine?
a.
bicycle
b.
can opener
c.
pulley
d.
scissor


____ 17. Jacob is pushing a shopping cart down a supermarket aisle. He is exerting forces in different directions on the shopping cart handle. Which force is doing the work?
a.
downward force
b.
forward force
c.
right angle force
d.
upward force


____ 18. Which response best describes power?
a.
The distance an object is moved.
b.
The force exerted on an object.
c.
The motion of an object.
d.
The rate at which work is done.


____ 19. In which way can a machine NOT make work easier?
a.
changing the amount of force needed
b.
changing the distance over which force is exerted
c.
changing the direction in which force is exerted
d.
changing the work by creating a new force


____ 20. Joey used a knife to cut a piece of bread. What is the work he applied to the knife called?
a.
friction
b.
input force
c.
mechanical advantage
d.
output force


____ 21. Hu made a chart to show the efficiency of three different machines.


Which machine has the highest ratio of output work to input work?
a.
Machine 1
b.
Machine 2
c.
Machine 3
d.
cannot tell


____ 22. Which is an example of a wheel and axle?
a.
baseball bat
b.
doorknob
c.
pulley
d.
screw


____ 23. How are an inclined plane and a wedge alike?
a.
Both have a flat, sloped surface.
b.
Both are compound machines.
c.
Both have the same mechanical advantage.
d.
Both have the same output force.


____ 24. Darren draws a diagram to show the forces exerted on an object. The arrows represent equal forces on the object.


How will the object be affected by the two equal forces?
a.
It will break.
b.
It will change direction.
c.
It will not be affected.
d.
It will not move.


____ 25. Which word best describes the ratio of an output force to an input force?
a.
distance
b.
efficiency
c.
friction
d.
mechanical advantage


____ 26. How does friction affect a machine’s efficiency?
a.
It increases it.
b.
It decreases it.
c.
It keeps it consistent.
d.
It does not affect it.


____ 27. The work equation states that work in joules equals force in newtons times distance in meters. If Sarah carries a box that weighs 35 N a distance of 3 m, how much work did she do?
a.
38 J
b.
70 J
c.
105 J
d.
175 J


____ 28. Tammy is standing still while holding a ten-pound bowling ball. Is she doing work?
a.
Yes, the ball is heavy.
b.
Yes, she is exerting a force on the object.
c.
No, she is not making the object move.
d.
No, she is exerting a force on the ground.


____ 29. Which one of the following is NOT an example of work being done?
a.
the Moon orbiting Earth
b.
pushing a box from the bottom of a hill to the top of the hill
c.
pulling a sled across a field covered with snow
d.
lifting a bookbag off the floor


____ 30. A fixed, single pulley that is used to lift a block does which one of the following?
a.
doubles the force required to lift the block
b.
decreases the force required to lift the block
c.
makes the block easier to lift by changing the direction of the force needed to lift it
d.
decreases the force required and changes the direction of the force required


____ 31. A slanted surface used to raise an object is a(n)____.
a.
efficiency board
c.
inclined plane
b.
effort ramp
d.
wedge


____ 32. A device that does work with only one movement and changes the size or direction of a force is a(n) ____.
a.
compound machine
c.
screw
b.
effort machine
d.
simple machine


____ 33. A bar that is free to pivot about a fixed point is a ____.
a.
fulcrum
c.
ramp
b.
lever
d.
wedge


____ 34. The rate at which work is done is called ____.
a.
efficiency
c.
force
b.
effort time
d.
power


____ 35. The work output of a machine divided by the work input is the ____ of the machine.
a.
efficiency
c.
power
b.
effort
d.
resistance


____ 36. The amount by which a machine multiplies an input force is called the ____.
a.
efficiency factor
c.
mechanical advantage
b.
fulcrum
d.
resistance force


____ 37. An inclined plane with one or two sloping sides forms a machine called a ____.
a.
pulley
c.
ramp
b.
lever
d.
wedge


____ 38. An inclined plane wrapped around a cylinder post is a ____.
a.
lever
c.
screw
b.
ramp
d.
wedge


____ 39. A machine that changes only the direction of a force has a mechanical advantage of ____.
a.
1
c.
10
b.
2
d.
100


____ 40. A winding mountain road is an example of a(n) ____.
a.
lever
c.
wedge
b.
inclined plane
d.
wheel and axle


____ 41. When two or more simple machines work together, they are called a(n) ____.
a.
compound machine
c.
screw
b.
effort machine
d.
simple machine


____ 42. A lever with a mechanical advantage greater than 1 is used to ____.
a.
change direction
c.
increase force
b.
increase distance
d.
decrease force


____ 43. Three of the following simple machines are basically the same. The one that does NOT belong with the group is the ____.
a.
lever
c.
wedge
b.
pulley
d.
wheel and axle


____ 44. An object is moving due east. You push the object. Work is being done at all times when you push ____.
a.
due west
c.
straight down
b.
due east
d.
at a 45° angle


____ 45. A ____ is an example of a compound machine.
a.
lawnmower
c.
baseball bat
b.
shovel
d.
wheel and axle


____ 46. The mechanical advantage tells you the number of times a machine increases the ____.
a.
net force
c.
output force
b.
stable force
d.
input force


____ 47. Work is equal to force times ____.
a.
power
c.
joules
b.
distance
d.
energy


____ 48. Power is measured in J per ____.
a.
watt
c.
minute
b.
hour
d.
second


____ 49. In order for work to be done, an object must ____.
a.
have mass
c.
have muscles
b.
move in the direction of the force
d.
move at a right angle to the force


____ 50. Machines let you use less force over a greater ____.
a.
distance
c.
weight
b.
mass
d.
exertion


____ 51. NO work is being done when you ____ a ball.
a.
hit
c.
carry
b.
catch
d.
drop


____ 52. When the Egyptians built the pyramids, they used the idea that a large force over a short distance can be accomplished by the same work as a small force over a ____ distance.
a.
changing
c.
shorter
b.
minimum
d.
long


____ 53. ____ describes the rate at which work is being done.
a.
Joules
c.
Effort force
b.
Power
d.
Efficiency


____ 54. A ____ is NOT a simple machine.
a.
wrench
c.
tooth
b.
shovel
d.
teeter-totter


____ 55. The pivot point of a lever is called a ____.
a.
wedge
c.
fulcrum
b.
screw
d.
wheel and axle


____ 56. Power is expressed in units of ____.
a.
light
c.
joules
b.
watts
d.
surges


____ 57. A(n) ____ is a moving inclined plane.
a.
teeter-totter
c.
elevator
b.
staircase
d.
wedge


Completion
Complete each statement.

58. When force is _________________________ to the direction of motion, no work is done.

59. A joule is equal to one ____________________ times one meter.

60. When you use a crowbar to lift a large rock, you are working against the force called ____________________.

61. Power describes the ____________________ at which work is being done.

62. Unlike a fixed pulley, a movable pulley ____________________ the input force.

63. Doorknobs and faucet handles are examples of a simple machine called a(n) ______________________________.

64. An ideal machine has an efficiency of ____________________.

65. The pivot point of a lever is called the ____________________.

66. A machine made of several simple machines is called a(n) ______________________________.

67. When a machine is used to perform a task, work output is always ____________________ than work input.

Choose the term in parentheses that correctly completes the sentence.

68. A blender is a ____________________ (simple, compound, pulley) machine.

69. The mechanical advantage that makes work easiest is one that is ____________________ (large, small, zero).

70. Holding a watermelon in your hands is an example of ____________________ (work, no work) being done.

71. A goalie stopping a hockey puck is an example of ____________________ (work, no work) being done.

72. Power does NOT depend on ____________________ (work done, muscles, time).

73. As you increase the effort distance, you ____________________ (decrease, increase, stabilize) the effort force needed.

74. The mechanical advantage tells you the number of times a machine ____________________ (increases, decreases, eliminates) the effort force.

75. A ____________________ (shovel, crowbar, potter’s wheel) is NOT an example of a lever.

76. An ideal machine has an efficiency ____________________ (less than one, equal to one, greater than one).

77. ____________________ (Heat, Friction, Work) is NOT a source of energy loss in a machine.

Matching

Match each term with the following questions.
a.
input force
d.
output force
b.
efficiency
e.
compound machine
c.
mechanical advantage



____ 78. ratio of output force to input force

____ 79. force you apply to a simple machine

____ 80. force you overcome when using a simple machine

____ 81. device made of more than one simple machine

____ 82. ability of a machine to convert work input into work output

Match each simple machine with the machines below.
a.
inclined plane
d.
lever
b.
wedge
e.
wheel and axle
c.
screw



____ 83. knife

____ 84. leaf rake

____ 85. wheelchair ramp

____ 86. potter's wheel

____ 87. threaded bolt

Match each item with the correct description below.
a.
simple machine
j.
watt
b.
work
k.
ideal machine
c.
input force
l.
screw
d.
inclined plane
m.
pulley
e.
joule
n.
mechanical advantage
f.
output force
o.
efficiency
g.
power
p.
fulcrum
h.
machine
q.
wheel and axle
i.
friction
r.
wedge


____ 88. a device that makes work easier by changing the size or direction of the applied force

____ 89. SI unit for work

____ 90. causes the output work of a machine to be less than the input work

____ 91. the rate at which work is being done

____ 92. the ratio of the output force to the input force

____ 93. a moving inclined plane

____ 94. has only one movement

____ 95. the unit of measurement of power

____ 96. two rigidly attached wheels that rotate together

____ 97. a sloped surface

____ 98. exertion of a force on an object that produces motion in the direction of the force

____ 99. the force a machine exerts

____ 100. a machine’s ability to convert work input into work output

____ 101. machine with 100% efficiency

____ 102. the pivot point of a lever

____ 103. an inclined plane wrapped around a shaft

____ 104. a grooved wheel that redirects force using a rope

____ 105. the effort force you exert

Short Answer

106.
Explain how a wheel and axle works and give examples of objects that use a wheel and axle.

107.
Sharon wants to know if friction will affect the efficiency of a ramp that she built. She will form a hypothesis and then test it.

Part A Write a hypothesis that Sharon can test.

Part B Write a plan that shows how Sharon can test her hypothesis.

108.
What does work depend on in scientific terms?

109.
You swing a rope in a circle. Are you doing work on the rope? Why or why not?

110.
Which one of the following could be the mechanical advantage of a third-class lever: 0.7, 1.5, 10.5, or 3.0? Explain your answer.

111.
An inventor claims to have built a machine that can produce 120 J of work with an input of 110 J. Would you believe the inventor's claim? Why or why not?

112.
Explain why tin snips, designed for cutting metal, have long handles and short blades.

113.
How are work, time, and power related?

114.
Gears are modified wheel-and-axle machines. Explain how to calculate the mechanical advantage of a pair of gears.

115.
A 700-watt gasoline engine and a 300-watt electric motor both do 3 J of work. Which machine can do the work faster? Explain your answer.

116.
How does low air pressure in bicycle tires reduce the efficiency of a bicycle?

117.
Give one example of a compound machine and list the simple machines that make it up.

118.
Do machines make work easier? Explain your answer.

119.
How does oil reduce friction between two surfaces?

120.
Explain how your teeth work as a wedge.

121.
Explain the transfer of energy during work.

Complete the table below by calculating the missing values. Then answer the following questions.

Situation
Force
Distance
Time
Work
Power
1. A
200 N
50 m
10 s


2. B
100 N
6 m


200 W
3. C
200 N
100 m
10 s


4. D
200 N

10 s
5000 J



122. What are the missing values in line 1?

123. What are the missing values in line 2?

124. What are the missing values in line 3?

125. What are the missing values in line 4?

126. In which situation was the most work done?

127. In which situation was the most power used?

128. How does the work done in situation D compare to that done in situation A?

129. How does the distance in situation D compare to the distance in situation A?

130. What would happen to the power in situation C if the time doubled?

131. Compare and contrast simple and compound machines.

132. Compare and contrast a screw and a wedge.

133. What is the work done in using a force of 200 N to push a box 15 m?

134. What is the power used if it took 2,000 J to move a box in 8 s?

135. What is the mechanical advantage of using a machine if you use an input force of 25 N to overcome an output force of 125 N?

136. If an output force of 50 N is used to move an object a distance of 20 m, what distance must the object be moved if the input force is 10 N, so that work in = work out?

137. What is the efficiency of a machine if the work input is 75 N and the work output is 25 N?

Problem

138.
You use 200 N of force to push a snow shovel 10 m along the ground. How much work was done?

139.
A painter lifts a 3 kg can of paint 3 m above the floor. How much work was done?

140.
How much power is needed to do 1,000 J of work on a box if it takes 50 s to lift it?

141.
How much work is done if 500 W of power is used over 2 min?

142.
Calculate the mechanical advantage of a lever where 5 N of input force is needed to move a 10 N box using that lever.

143.
A carpenter uses a claw hammer to pull a nail from a board. The nail has a resistance of 1,500 N. The carpenter applies a force of 150 N. What is the mechanical advantage of the hammer?

Essay

144. Name the six types of simple machines and give an example of each, or what each might be used to do.

145. Explain why applying force to an object does not always result in work being done.

146. Even though work input should equal work output, explain why, other than on ideal machines, machines have an efficiency less than one.

147. If a machine cannot have more work output than work input, what advantage is there to using one?

148. Compare and contrast fixed pulleys with movable pulleys and pulley systems and discuss their respective mechanical advantages.
7th Grade - CHpater 5 ONLINE REVIEW
Answer Section

TRUE/FALSE

1. ANS: T PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.C.2.3.4

2. ANS: F PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.C.2.3.3

3. ANS: T PTS: 1 DIF: Webb's I OBJ: 2/1

4. ANS: T PTS: 1 DIF: Webb's I OBJ: 2/1

5. ANS: F PTS: 1 DIF: Webb's I OBJ: 5/2
STA: SC.C.2.3.3 SC.C.2.3.4

6. ANS: T PTS: 1 DIF: Webb's I OBJ: 3/1
STA: SC.C.2.3.3

7. ANS: T PTS: 1 DIF: Webb's I OBJ: 3/1

8. ANS: T PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.C.2.3.4

9. ANS: F PTS: 1 DIF: Webb's I OBJ: 7/3

10. ANS: T PTS: 1 DIF: Webb's I OBJ: 8/3
STA: SC.C.2.3.4

11. ANS: F PTS: 1

12. ANS: F PTS: 1

13. ANS: T PTS: 1

14. ANS: T PTS: 1

15. ANS: T PTS: 1

MULTIPLE CHOICE

16. ANS: C PTS: 1 DIF: Webb's I STA: SC.C.2.3.4

17. ANS: B PTS: 1 DIF: Webb's I STA: SC.C.2.3.2 SC.C.2.3.3

18. ANS: D PTS: 1 DIF: Webb's I STA: SC.C.2.3.6

19. ANS: D PTS: 1 DIF: Webb's I STA: SC.C.2.3.4

20. ANS: B PTS: 1 DIF: Webb's II STA: SC.C.2.3.2

21. ANS: C PTS: 1 DIF: Webb's II STA: SC.C.2.3.6

22. ANS: B PTS: 1 DIF: Webb's II STA: SC.C.2.3.4

23. ANS: A PTS: 1 DIF: Webb's II STA: SC.C.2.3.4

24. ANS: B PTS: 1 DIF: Webb's II STA: SC.C.2.3.3 SC.C.2.3.4

25. ANS: D PTS: 1 DIF: Webb's I STA: SC.C.2.3.4

26. ANS: B PTS: 1 DIF: Webb's II STA: SC.C.2.3.4

27. ANS: C PTS: 1 DIF: Webb's II STA: SC.C.1.3.1

28. ANS: C PTS: 1 DIF: Webb's II STA: SC.C.2.3.2

29. ANS: A PTS: 1 DIF: Webb's II OBJ: 1/1
STA: SC.C.2.3.7

30. ANS: C PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.C.2.3.4

31. ANS: C PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.C.2.3.4

32. ANS: C PTS: 1 DIF: Webb's I OBJ: 4/2
STA: SC.C.2.3.4

33. ANS: B PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.C.2.3.4

34. ANS: D PTS: 1 DIF: Webb's I OBJ: 3/1

35. ANS: A PTS: 1 DIF: Webb's I OBJ: 5/2

36. ANS: C PTS: 1 DIF: Webb's I OBJ: 5/2
STA: SC.C.2.3.4

37. ANS: D PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.C.2.3.4

38. ANS: C PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.C.2.3.4

39. ANS: A PTS: 1 DIF: Webb's I OBJ: 5/2
STA: SC.C.2.3.4

40. ANS: B PTS: 1 DIF: Webb's I OBJ: 7/3

41. ANS: A PTS: 1 DIF: Webb's I OBJ: 7/3

42. ANS: C PTS: 1 DIF: Webb's I OBJ: 5/2
STA: SC.C.2.3.4

43. ANS: C PTS: 1 DIF: Webb's II OBJ: 7/3
STA: SC.C.2.3.4

44. ANS: B PTS: 1

45. ANS: A PTS: 1

46. ANS: D PTS: 1

47. ANS: B PTS: 1

48. ANS: D PTS: 1

49. ANS: B PTS: 1

50. ANS: A PTS: 1

51. ANS: C PTS: 1

52. ANS: D PTS: 1

53. ANS: B PTS: 1

54. ANS: A PTS: 1

55. ANS: C PTS: 1

56. ANS: B PTS: 1

57. ANS: D PTS: 1

COMPLETION

58. ANS: perpendicular

PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.C.2.3.3

59. ANS: newton

PTS: 1 DIF: Webb's I OBJ: 2/1

60. ANS: gravity

PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.C.2.3.1 SC.C.2.3.3 SC.C.2.3.4

61. ANS: rate

PTS: 1 DIF: Webb's I OBJ: 3/1

62. ANS: multiplies

PTS: 1 DIF: Webb's I OBJ: 7/3 STA: SC.C.2.3.4

63. ANS: wheel and axle

PTS: 1 DIF: Webb's I OBJ: 7/3 STA: SC.C.2.3.4

64. ANS: 100 percent

PTS: 1 DIF: Webb's I OBJ: 5/2 STA: SC.C.2.3.4

65. ANS: fulcrum

PTS: 1 DIF: Webb's I OBJ: 7/3

66. ANS: compound machine

PTS: 1 DIF: Webb's I OBJ: 7/3

67. ANS:
smaller
less

PTS: 1 DIF: Webb's I OBJ: 5/2 STA: SC.C.2.3.4

68. ANS: compound

PTS: 1

69. ANS: large

PTS: 1

70. ANS: no work

PTS: 1

71. ANS: work

PTS: 1

72. ANS: muscles

PTS: 1

73. ANS: decrease

PTS: 1

74. ANS: increases

PTS: 1

75. ANS: potter’s wheel

PTS: 1

76. ANS: equal to one

PTS: 1

77. ANS: Work

PTS: 1

MATCHING

78. ANS: C PTS: 1 DIF: Webb's I OBJ: 5/2

79. ANS: A PTS: 1 DIF: Webb's I OBJ: 5/2
STA: SC.C.2.3.4

80. ANS: D PTS: 1 DIF: Webb's I OBJ: 5/2
STA: SC.C.2.3.4

81. ANS: E PTS: 1 DIF: Webb's I OBJ: 7/3

82. ANS: B PTS: 1 DIF: Webb's I OBJ: 5/2
STA: SC.C.2.3.4

83. ANS: B PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.C.2.3.4

84. ANS: D PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.C.2.3.4

85. ANS: A PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.C.2.3.4

86. ANS: E PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.C.2.3.4

87. ANS: C PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.C.2.3.4

88. ANS: H PTS: 1

89. ANS: E PTS: 1

90. ANS: I PTS: 1

91. ANS: G PTS: 1

92. ANS: N PTS: 1

93. ANS: R PTS: 1

94. ANS: A PTS: 1

95. ANS: J PTS: 1

96. ANS: Q PTS: 1

97. ANS: D PTS: 1

98. ANS: B PTS: 1

99. ANS: F PTS: 1

100. ANS: O PTS: 1

101. ANS: K PTS: 1

102. ANS: P PTS: 1

103. ANS: L PTS: 1

104. ANS: M PTS: 1

105. ANS: C PTS: 1

SHORT ANSWER

106. ANS:
A wheel and axle is composed of two circular objects of different diameters that are attached so that they rotate together. Examples of a wheel and axle where a force is used to turn the axle are a fan or a Ferris wheel. Examples where a force is used to turn the wheel are a doorknob or a steering wheel.

PTS: 1 DIF: Webb's II STA: SC.C.2.3.4

107. ANS:
Part A Hypotheses will vary, but a possible one is “Friction will affect the efficiency of a ramp. It will slow down objects traveling on the ramp.”

Part B Plans will vary, but a possible one includes setting up two ramps that are identical in length, height, and smooth material for the surface. The only difference is that one ramp (the control) will have nothing on the smooth surface, and the other ramp (the variable) will have a rough material such as sandpaper, carpet, or cloth covering the ramp’s smooth surface. Objects moving down the ramps will be timed and the results recorded. Repeated trials are suggested so that the results are more reliable.

PTS: 1 DIF: Webb's III STA: SC.C.2.3.2 SC.C.2.3.5 SC.C.2.3.6

108. ANS:
Work depends on the force applied to the object and the distance the object is moved.

PTS: 1 DIF: Webb's II OBJ: 1/1

109. ANS:
No, the force applied to the rope is not in the same direction as the motion of the rope.

PTS: 1 DIF: Webb's II OBJ: 1/1

110. ANS:
0.7, because the mechanical advantage of a third-class lever is always less than one.

PTS: 1 DIF: Webb's II OBJ: 5/2 STA: SC.C.2.3.4

111. ANS:
No. The machine would have an efficiency of 108%. This is not possible since machines cannot have an efficiency greater than 100%.

PTS: 1 DIF: Webb's II OBJ: 5/2 STA: SC.C.2.3.4

112. ANS:
The mechanical advantage for scissors, a first-class lever, is the length of the handle divided by the length of the blade. Cutting hard materials requires a high mechanical advantage.

PTS: 1 DIF: Webb's II OBJ: 5/2

113. ANS:
Power is the measure of work done per unit of time.

PTS: 1 DIF: Webb's II OBJ: 3/1

114. ANS:
Divide the radius of the wheel by the radius of the axle.

PTS: 1 DIF: Webb's II OBJ: 8/3 STA: SC.C.2.3.4

115. ANS:
The 700-watt engine does the work faster because it takes a smaller amount of time to do the work.

PTS: 1 DIF: Webb's II OBJ: 2/1

116. ANS:
Low air increases the friction between the tire and the road. This reduces efficiency.

PTS: 1 DIF: Webb's II OBJ: 5/2 STA: SC.C.2.3.2

117. ANS:
Sample answer: a lawnmower is made up of a lever, wheel and axle, and wedge.

PTS: 1 DIF: Webb's II OBJ: 7/3

118. ANS:
Machines do not change the amount of work needed to do something. They just allow you to use less force over a longer distance.

PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.C.2.3.4

119. ANS:
Oil fills the gaps between surfaces and prevents many spots on the surfaces from coming in contact, reducing the force of friction.

PTS: 1 DIF: Webb's II OBJ: 6/2 STA: SC.C.2.3.2

120. ANS:
A wedge changes the direction of applied force. When you push your teeth into an apple the downward effort force is changed to a sideways force that pushes the apple apart.

PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.C.2.3.4

121. ANS:
When something is moving it has kinetic energy. By lifting an object you increase its potential energy. As you perform work, energy is transferred from you to the object you are working on.

PTS: 1 DIF: Webb's II OBJ: 3/1 STA: SC.C.2.3.5

122. ANS:
10,000 J; 1,000 W

PTS: 1

123. ANS:
3 s; 600 J

PTS: 1

124. ANS:
20,000 J; 2,000 W

PTS: 1

125. ANS:
25 m; 500 W

PTS: 1

126. ANS:
C

PTS: 1

127. ANS:
C

PTS: 1

128. ANS:
Half as much work is done.

PTS: 1

129. ANS:
It is half as far.

PTS: 1

130. ANS:
The power would be half as much.

PTS: 1

131. ANS:
A simple machine has only one movement. A compound machine is made up of two or more simple machines. Both make work easier by changing the size or direction of the force applied to an object to do work.

PTS: 1

132. ANS:
Both are inclined planes. A screw is an inclined plane wrapped around a cylinder. A wedge is an inclined plane that moves.

PTS: 1

133. ANS:
W = F ´ d = 200 ´ 15 = 3,000 J

PTS: 1

134. ANS:

PTS: 1

135. ANS:

PTS: 1

136. ANS:

PTS: 1

137. ANS:

PTS: 1

PROBLEM

138. ANS:
W = F ´ d = 200 N ´ 10 m = 2,000 J

PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.C.2.3.2

139. ANS:
W = m ´ g ´ d = 3 kg ´ 9.8 m/s2 ´ 3 m = 88 J

PTS: 1 DIF: Webb's II OBJ: 2/1

140. ANS:
P = W/t = 1,000 J/50 s = 20 W

PTS: 1 DIF: Webb's II OBJ: 3/1

141. ANS:
W = P ´ t = 500 W ´ 120 s = 60,000 J

PTS: 1 DIF: Webb's II OBJ: 3/1

142. ANS:
M.A. = Resistance Force/Force = 10 N/5 N = 2

PTS: 1 DIF: Webb's II OBJ: 5/2 STA: SC.C.2.3.4

143. ANS:
M.A. = Resistance Force/Force = 1,500 N/150 N = 10

PTS: 1 DIF: Webb's II OBJ: 3/1 STA: SC.C.2.3.4

ESSAY

144. ANS:
1. inclined plane—ramp to move furniture onto truck
2. wedge—axe, knife blade
3. screw—base of lightbulb, jar lid
4. lever—wheelbarrow, shovel, jack to lift car to change tire
5. wheel and axle—steering wheel, door knob, electric pencil sharpener
6. pulley—window blinds, drapes, painters’ scaffolds

PTS: 1

145. ANS:
The object may not move. The object must move in the direction of the applied force in order for work to be done.

PTS: 1

146. ANS:
Energy, therefore work, is lost due to heat loss and friction in a machine.

PTS: 1

147. ANS:
A machine makes work easier by changing the amount of force you need to exert, the distance over which the force is exerted, or the direction in which you exert your force.

PTS: 1

148. ANS:
A fixed pulley changes the direction in which a force is exerted and has a mechanical advantage of 1. A movable pulley attached to the object being lifted allows for the exertion of a smaller force to lift the object. The mechanical advantage of a movable pulley is 2. A pulley system is a combination of fixed and movable pulleys and has a mechanical advantage equal to the number of sections of rope pulling on the object.

PTS: 1

7th Grade- Chapter 4 Online Review

7th Grade - CHpater 4 ONLINE REVEIW

Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.

____ 1. To locate a mall close to you, you need to know it's distance. _________________________

____ 2. The speed you read on your speedometer is the constant speed. _________________________

____ 3. When you ride your bike around a corner at 10 m/s, you are accelerating. _________________________

____ 4. To determine if an object has changed position, you need to know it's position relative to another object. _________________________

____ 5. Acceleration is caused by any forces. _________________________

____ 6. An example of a contact force is magnetism. _________________________

____ 7. You push on a book and it moves. The forces acting on it must be action-reaction forces. _________________________

____ 8. If an unbalanced force is acting on a rope, the rope will accelerate in the direction of the unbalanced force. _________________________

____ 9. If an astronaut were to land on Jupiter, his mass would increase. _________________________

____ 10. An insect falls from a twenty-story building and walks away when he hits the sidewalk because of contact forces. _________________________

____ 11. Sliding friction keeps you in the seat when a car goes around a corner. _________________________

____ 12. Forces always occur alone. _________________________

____ 13. If you throw a ball into the air, Earth exerts a force on the ball. The ball in the air exerts no force. _________________________

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____ 14. Electric, magnetic, and gravitational forces are all examples of which type of force?
a.
balanced
b.
contact
c.
non-contact
d.
unbalanced


____ 15. Which of the following has a net force of zero?
a.
balanced force
b.
buoyant force
c.
gravitational force
d.
unbalanced force


____ 16. Max is pushing a book across a table. When he stops pushing, the book slows down and stops. This is an example of which force?
a.
air resistance
b.
buoyancy
c.
gravity
d.
sliding friction


____ 17. When does a gravitational force between two objects increase?
a.
when the mass of the objects increases
b.
when the speed of the objects increases
c.
when the mass of the objects decreases
d.
when the speed of the objects decreases


____ 18. An object at rest remains at rest. An object in motion keeps moving in a straight line at a constant speed. Which of Newton’s laws of motion does this describe?
a.
first law
b.
second law
c.
third law
d.
first and third laws together


____ 19. Mark is traveling 3 mi north at 2 mph. Which of the following can be figured out with this information?
a.
acceleration
b.
average speed
c.
displacement
d.
velocity


____ 20. Susan made a diagram to show how the relationship between a buoyant force and gravity.


Which answer BEST describes the relationship shown in the diagram?
a.
Buoyancy and gravity together balance an object.
b.
Buoyant forces move at a faster rate than gravity.
c.
Gravity is more powerful than buoyancy.
d.
Objects do not know whether they will be pulled up or down


____ 21. Which law of motion says that the ground pushes back on you when you push down on it?
a.
first law
b.
second law
c.
third law
d.
fourth law


____ 22. The Average Speed equation states that average speed in meters per second equals distance in meters divided by time in seconds. If Jan travels 63 m in 7 s, what is her average speed?
a.
7 m/s
b.
9 m/s
c.
14 m/s
d.
63 m/s


____ 23. When is an object NOT accelerating?
a.
when it changes speed
b.
when it changes direction
c.
when it changes force
d.
when it changes velocity


____ 24. Donna measured the displacement and time for a traveling object.


What is the velocity of the object?
a.
2 km/h south
b.
3 km/h south
c.
4 km/h south
d.
6 km/h south


____ 25. According to Newton’s second law of motion, how is acceleration related to net force?
a.
When net force on an object increases, acceleration increases.
b.
When net force on an object decreases, acceleration increases.
c.
When acceleration changes, net force stays the same.
d.
When net force changes, acceleration stays the same.


____ 26. Which statement best describes Newton’s third law of motion?
a.
All forces are equal.
b.
An object at rest tends to stay at rest.
c.
Forces always act in pairs.
d.
Some forces have no reaction.


____ 27. Motion is change in ____.
a.
speed
c.
force
b.
velocity
d.
position


____ 28. ____ is rate of change of position.
a.
Speed
c.
Acceleration
b.
Velocity
d.
Displacement


____ 29. You travel 200 km in 2 h. Your ____ speed is 100 km/h.
a.
constant
c.
instantaneous
b.
average
d.
initial


____ 30. When a car slows down at a traffic light, it is ____.
a.
accelerating
c.
decreasing its displacement
b.
traveling at constant velocity
d.
changing direction


____ 31. You hear that a storm is moving 15 km/h north. You have been given the storm's ____.
a.
constant speed
c.
velocity
b.
acceleration
d.
average speed


____ 32. Inertia is a measure of the ____ of an object.
a.
weight
c.
constant speed
b.
mass
d.
acceleration


____ 33. The unit of force is ____.
a.
m/s
c.
the joule
b.
the hertz
d.
the newton


____ 34. When two birds are pulling on a worm and the worm moves toward the first bird, you know that the forces are ____.
a.
long-range
c.
unbalanced
b.
action-reaction
d.
balanced


____ 35. An unbalanced force acting on an object causes it to ____.
a.
move at constant speed
c.
not change its velocity
b.
continue in a straight line
d.
accelerate


____ 36. A planet is discovered that is the same size as Earth and has the same gravitational acceleration, but has twice the mass. If you weigh 700 N on Earth, on the new planet you would weigh ____.
a.
350 N
c.
1,400 N
b.
700 N
d.
2,800 N


____ 37. The force that opposes motion is ____.
a.
a balanced force
c.
an accelerating force
b.
an unbalanced force
d.
friction


____ 38. Every force has a(n) ____ force.
a.
reaction
c.
opposite
b.
long-range
d.
accelerating


____ 39. You throw a ball into the air. As the ball leaves your hand, the force(s) acting on it is/are ____.
a.
gravity
c.
balanced
b.
your hand
d.
gravity and your hand


Completion
Complete each statement.

40. If you walk one mile to a store and one mile back, your distance is ____________________ and your displacement is ____________________.

41. If you ride your bike 2 miles on a straight road between Gooseberry Junction and Happy Valley, your distance is ____________________ and your displacement is ____________________.

42. ____________________ is the change in velocity divided by the change in time.

43. Speeding up, slowing down, and going around curves are examples of ____________________.

44. If you are riding on a skateboard and it stops suddenly, your body keeps moving forward. This is because of ____________________.

45. A(n) ____________________ is a push or a pull.

46. Forces that change an object's motion by touching the object are ____________________ forces.

47. A spacecraft orbits the Earth at a constant speed. The forces acting on it must be ____________________.

48. Acceleration due to gravity at the Earth's surface is ____________________.

49. A car going around a corner, hits an icy path, and skids off the road. This represents a change from rolling friction to ____________________ friction.

50. Wagons have wheels instead of runners because ____________________ friction is less than ____________________ friction.

51. When you catch a ball, the ball creates force on your hand. The reaction force is ____________________.

52. If you throw a ball into the air, at the top of the path the force(s) acting on the ball is/are ____________________.

Choose the term or phrase that best completes each sentence.

53. If you drive from New York to San Francisco by way of Mt. Rushmore, Yellowstone National Park, and Branson, Missouri, your distance traveled is ____________________ (greater than, less than, the same as) your displacement.

54. When your feet push on the floor so that you can walk across the room, you move but the floor doesn’t. The force of the floor on your feet is ____________________ (greater than, less than, the same as) the force of your feet on the floor.

55. Standing still in a windstorm is an example of ____________________ (static, sliding, rolling) friction between your feet and the ground.

56. To push a box across the floor takes more force than to push the same box on wheels across the floor. This shows that rolling friction is ____________________ (greater than, less than, equal to) sliding friction.

57. In order to keep a race car going around a circular track at constant speed, ____________________ (no force, a balanced force, an unbalanced force) is needed.

58. A reaction force is created ____________________ (before, after, at the same time as) its action force.

59. The force needed to accelerate a full-size car to a given velocity is ____________________ (greater than, less than, equal to) the force needed to accelerate a motorcycle to the same velocity.

60. The displacement of a car driving a winding road up a mountain is ____________________ (greater than, less than, the same as) the distance the car travels.

61. When you push off of the side of a swimming pool, the force of your foot on the wall is created ____________________ (before, after, at the same time as) the force of the wall on your foot.

62. When a ball starts to fall through the air, the force of air resistance on the ball is ____________________ (greater than, less than, the same as) the force of gravity.

63. The mass of an astronaut ____________________ (increases, decreases, remains the same) when the astronaut goes on a space walk.

64. A crumpled piece of paper falls to the ground faster than a smooth piece because of ____________________.

65. When you push a book across your desk, the force of your hand is ____________________ the force of static friction.

66. The force needed to accelerate a bowling ball to a given velocity is ____________________ the force needed to accelerate a soccer ball to the same velocity.

67. A radio-controlled plane flies 75 m north, then 95 m south. Its ____________________ is 20 m south.

68. A car that travels 200 km in 2 h has a(n) ____________________ speed of 100 km/h.

69. ____________________ keeps you from sliding backward when you climb a hill.

70. ____________________ is the tendency of a body to resist change in its motion.

71. Forces always occur in equal but opposite ____________________.

Matching

Match each item with the correct description below.
a.
static friction
k.
Unbalanced forces
b.
force
l.
Acceleration
c.
rolling friction
m.
Inertia
d.
displacement
n.
Speed
e.
first law of motion
o.
Second law of motion
f.
Newton’s laws of motion
p.
Friction
g.
Sliding friction
q.
Air resistance
h.
Velocity
r.
Mass
i.
Balanced forces
s.
Newton (N)
j.
Third law of motion
t.
weight


____ 72. the distance and direction between starting and ending positions

____ 73. the distance traveled divided by the time needed to travel the distance

____ 74. change in velocity divided by the amount of time required for the change to occur

____ 75. displacement divided by time

____ 76. an object will remain at rest or move in a straight line with constant speed unless it is acted upon by a force

____ 77. equal forces that move in opposite directions

____ 78. a push or a pull

____ 79. forces that move in opposite directions that are not of equal strength

____ 80. a force that resists motion

____ 81. an object acted upon by an unbalanced force will accelerate in the direction of the force

____ 82. forces always act in equal but opposite pairs

____ 83. Air molecules act on the forward-moving surface of an object, slowing its motion.

____ 84. The type of friction that makes a tire turn and a ball roll is called ____.

____ 85. the friction that occurs when two surfaces slide past each other

____ 86. the friction that hinders a stationary object from moving on a surface when a force is applied to that object

____ 87. a force that can change when acceleration due to gravity changes

____ 88. a measure of the amount of matter in an object

____ 89. measures an object’s tendency to remain at rest or keep moving with constant velocity

____ 90. used to measure force

____ 91. a set of rules used to predict and explain motion

Match Newton’s laws of motion with the examples given.
a.
Newton’s first law
c.
Newton’s third law
b.
Newton’s second law



____ 92. A magician pulls the table cloth off a table, leaving the dishes on the table.

____ 93. A ball rolling across the floor eventually comes to a stop.

____ 94. A rower’s arms push the oars against the water. The boat moves forward after the water pushes against the oars.

____ 95. A rock moves slower when shot out of a slingshot than a pebble shot out of the same slingshot.

____ 96. You jump off a raft in the swimming pool, and when you turn around to get back on the raft, the raft has floated off in the opposite direction.

Match the unit with the quantity it measures.
a.
second
d.
m/s2
b.
newton
e.
meter
c.
m/s



____ 97. speed

____ 98. distance

____ 99. force

____ 100. time

____ 101. acceleration

Short Answer

102.
Explain the difference between speed and velocity.

103.
Mr. French’s class is using a toy car to study Newton’s laws of motion.

Part A What does Newton’s first law state?

Part B Give an example of how the class can use the toy car to demonstrate how the law works.

104.
Compare and contrast distance and displacement.

105.
Compare and contrast speed and velocity.

106.
If you run three laps around a circular race track at 5 m/s, what do you know about your speed, velocity, and acceleration?

107.
Is it necessary for an object to be in motion if it has forces acting on it? Why or why not?

108.
"If no forces are acting on a moving object, it will eventually come to rest." Comment on this statement.

109.
If you were playing football on the space station, would it be as hard to stop a 150-kg lineman as it would be on Earth? Why or why not?

110.
How is force similar to displacement and velocity?

111.
You drop a pebble from a bridge and it goes faster and faster before it hits the water. What do you know about the forces acting on the pebble?

112.
If a body is in motion at constant speed in a straight line, what, if any, forces could be acting on it?

113.
How could you decrease the force a horse needed to pull a wagonload of hay?

114.
For a long time, all experiments showed that a force had to be applied to keep a body in motion at constant velocity. How does our knowledge of the force of friction help us to understand, now, that this isn't true?

Figure 23-1

115.
In Figure 23-1, identify two pairs of action-reaction forces involving the rope.

116.
In Figure 23-1, identify two balanced forces involving the rope.

117.
In Figure 23-1, if the black dog starts pulling on the rope harder than the white dog, what will happen to the rope?

118.
In Figure 23-1, how could the rope-on-black-dog force be increased?

119.
In Figure 23-1, if the rope moves toward the white dog, what do you know about the forces on the rope?

120.
If you throw a ball into the air, after it leaves your hand, what is/are the net force(s) acting on it? Describe the ball's acceleration.

121. A high speed train travels south for 2.00 h for a distance of 454 km. What is its average velocity?

122. A coasting car slows down from 27 m/s to 24 m/s in 6 s. What is the car’s acceleration?

123. Calculate the force necessary to accelerate a 0.14-kg hardball at a rate of 100 m/s2.

124. A car travels 528 km in six hours. Find its average speed.

125. The maximum acceleration of a fist in a karate punch is 3800 m/s2. The mass of the fist is 0.70 kg. If the fist hits a wooden block, what force does the wood place on the fist?

126. When a ball is dropped it is easy to see that Earth exerts a force on it. Why can’t you tell that the ball exerts a force on Earth?

127. If you and your friend ride bumper cars at the fair, what happens, in terms of Newton’s third law, when they collide?

128. If you bump into a heavy desk sitting on a carpet, it doesn’t move. Explain.

129. Is it possible to have a single force? Explain why or why not.

130. It has been found that when a karate blow of a fist strikes a wooden block, the block can exert a force of 2,450 N on the hand. What force must be put on the block to break it?

Problem

131.
0.30 s after seeing a puff of smoke rise from the starter's pistol, the sound of the firing of the pistol is heard by the track timer 100 m away. What is the speed of sound?

132.
A top-fuel dragster accelerates from rest to a velocity of 100 m/s in 8 s. What is the acceleration?

133.
On Planet Zorg, a 30-kg barbell can be lifted by only exerting a force of 180 N. What is the acceleration of gravity on Planet Zorg?

134.
A racing car has a mass of 750 kg. It undergoes an acceleration of 4.00 m/s2. What is the net force acting on the car?

Essay

135. An astronaut in the space shuttle turns a screwdriver clockwise. The astronaut starts to rotate in a counterclockwise direction. Why does this happen?

136. You are worried about a severe storm in your area. You hear a weather broadcast that says that the storm is moving at a speed of 25 km/h. Is this all you need to know for safety? Explain why or why not in terms of speed and velocity.

137. You ride three full turns around on a merry-go-round horse. What is your displacement? Your speed is constant; is your velocity constant? Why or why not?

138. A dog on a chain is fastened to the side of a house.
a. As the dog pulls on the end of the chain, name two pairs of action-reaction forces acting on the chain.
b. What are the balanced forces on the chain?
c. What happens to the forces on the chain if the dog pulls the chain away from the wall and runs to play?
7th Grade - CHpater 4 ONLINE REVEIW
Answer Section

MODIFIED TRUE/FALSE

1. ANS: F, displacement

PTS: 1 DIF: Webb's I OBJ: 1/1 STA: SC.C.1.3.1

2. ANS: F, instantaneous

PTS: 1 DIF: Webb's I OBJ: 2/1 STA: SC.C.1.3.1

3. ANS: T PTS: 1 DIF: Webb's I
OBJ: 2/1 STA: SC.C.1.3.1

4. ANS: T PTS: 1 DIF: Webb's I
OBJ: 1/1 STA: SC.C.1.3.1

5. ANS: F, unbalanced

PTS: 1 DIF: Webb's I OBJ: 6/2 STA: SC.C.1.3.1

6. ANS: F, long-range

PTS: 1 DIF: Webb's I OBJ: 4/2 STA: SC.C.2.3.1 SC.C.2.3.2

7. ANS: F, unbalanced

PTS: 1 DIF: Webb's I OBJ: 6/2 STA: SC.C.2.3.2 SC.C.2.3.6

8. ANS: T PTS: 1 DIF: Webb's I
OBJ: 6/2 STA: SC.C.2.3.6

9. ANS: F, remain the same

PTS: 1 DIF: Webb's I OBJ: 7/3

10. ANS: F, air resistance

PTS: 1 DIF: Webb's I OBJ: 8/3 STA: SC.C.2.3.2

11. ANS: F, Static

PTS: 1 DIF: Webb's I OBJ: 8/3 STA: SC.C.2.3.2

12. ANS: F, in pairs

PTS: 1 DIF: Webb's I OBJ: 10/4 STA: SC.C.2.3.2 SC.C.2.3.6

13. ANS: F, a force on Earth

PTS: 1 DIF: Webb's I OBJ: 11/4 STA: SC.C.2.3.1

MULTIPLE CHOICE

14. ANS: C PTS: 1 DIF: Webb's I STA: SC.C.2.3.1

15. ANS: A PTS: 1 DIF: Webb's I STA: SC.C.2.3.3

16. ANS: D PTS: 1 DIF: Webb's II STA: SC.C.2.3.2 SC.C.2.3.3

17. ANS: A PTS: 1 DIF: Webb's II STA: SC.C.2.3.7

18. ANS: A PTS: 1 DIF: Webb's I STA: SC.C.2.3.5

19. ANS: D PTS: 1 DIF: Webb's I STA: SC.C.1.3.1

20. ANS: C PTS: 1 DIF: Webb's II STA: SC.C.2.3.1

21. ANS: C PTS: 1 DIF: Webb's II STA: SC.C.2.3.3

22. ANS: B PTS: 1 DIF: Webb's II STA: SC.C.1.3.1

23. ANS: C PTS: 1 DIF: Webb's I STA: SC.C.1.3.1

24. ANS: B PTS: 1 DIF: Webb's II STA: SC.C.1.3.1

25. ANS: A PTS: 1 DIF: Webb's II STA: SC.C.2.3.6

26. ANS: C PTS: 1 DIF: Webb's II STA: SC.C.2.3.3

27. ANS: D PTS: 1 DIF: Webb's I OBJ: 1/1
STA: SC.C.1.3.1

28. ANS: A PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.C.1.3.1

29. ANS: B PTS: 1 DIF: Webb's I OBJ: 3/1
STA: SC.C.1.3.1

30. ANS: A PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.C.1.3.1 SC.C.2.3.3 SC.C.2.3.5

31. ANS: C PTS: 1 DIF: Webb's I OBJ: 2/1
STA: SC.C.1.3.1

32. ANS: B PTS: 1 DIF: Webb's I OBJ: 5/2

33. ANS: D PTS: 1 DIF: Webb's I OBJ: 4/2

34. ANS: C PTS: 1 DIF: Webb's I OBJ: 6/2
STA: SC.C.2.3.2

35. ANS: D PTS: 1 DIF: Webb's I OBJ: 10/4
STA: SC.C.2.3.2

36. ANS: C PTS: 1 DIF: Webb's I OBJ: 7/3
STA: SC.A.1.3.2 SC.C.2.3.1

37. ANS: D PTS: 1 DIF: Webb's I OBJ: 8/3
STA: SC.C.2.3.2 SC.C.2.3.5

38. ANS: C PTS: 1 DIF: Webb's I OBJ: 10/4
STA: SC.C.2.3.3

39. ANS: D PTS: 1 DIF: Webb's I OBJ: 10/4
STA: SC.C.2.3.1

COMPLETION

40. ANS: 2 miles, 0

PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.C.1.3.1

41. ANS: 2 miles, 2 miles

PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.C.1.3.1

42. ANS: Acceleration

PTS: 1 DIF: Webb's I OBJ: 2/1 STA: SC.C.1.3.1

43. ANS: acceleration

PTS: 1 DIF: Webb's I OBJ: 2/1 STA: SC.C.1.3.1

44. ANS: inertia

PTS: 1 DIF: Webb's I OBJ: 5/2 STA: SC.C.2.3.6

45. ANS: force

PTS: 1 DIF: Webb's I OBJ: 4/2 STA: SC.C.2.3.1 SC.C.2.3.2

46. ANS: contact

PTS: 1 DIF: Webb's I OBJ: 4/2 STA: SC.C.2.3.2

47. ANS: balanced

PTS: 1 DIF: Webb's I OBJ: 6/2 STA: SC.C.2.3.1 SC.C.2.3.6

48. ANS: 9.8m/sec2

PTS: 1 DIF: Webb's I OBJ: 7/3 STA: SC.C.2.3.1

49. ANS: sliding

PTS: 1 DIF: Webb's I OBJ: 8/3 STA: SC.C.2.3.5

50. ANS: rolling, sliding

PTS: 1 DIF: Webb's II OBJ: 8/3 STA: SC.C.2.3.2

51. ANS: hand-on-ball

PTS: 1 DIF: Webb's II OBJ: 10/4 STA: SC.C.2.3.2

52. ANS: gravity, air resistance

PTS: 1 DIF: Webb's II OBJ: 10/4 STA: SC.C.2.3.2 SC.C.2.3.3

53. ANS: greater than

PTS: 1

54. ANS: the same as

PTS: 1

55. ANS: static

PTS: 1

56. ANS: less than

PTS: 1

57. ANS: an unbalanced force

PTS: 1

58. ANS: at the same time as

PTS: 1

59. ANS: greater than

PTS: 1

60. ANS: less than

PTS: 1

61. ANS: at the same time as

PTS: 1

62. ANS: less than

PTS: 1

63. ANS: remains the same

PTS: 1

64. ANS: air resistance

PTS: 1

65. ANS: greater than

PTS: 1

66. ANS: less than

PTS: 1

67. ANS: displacement

PTS: 1

68. ANS: average

PTS: 1

69. ANS: friction

PTS: 1

70. ANS: inertia

PTS: 1

71. ANS: pairs

PTS: 1

MATCHING

72. ANS: D PTS: 1

73. ANS: N PTS: 1

74. ANS: L PTS: 1

75. ANS: H PTS: 1

76. ANS: E PTS: 1

77. ANS: I PTS: 1

78. ANS: B PTS: 1

79. ANS: K PTS: 1

80. ANS: P PTS: 1

81. ANS: O PTS: 1

82. ANS: J PTS: 1

83. ANS: Q PTS: 1

84. ANS: C PTS: 1

85. ANS: G PTS: 1

86. ANS: A PTS: 1

87. ANS: T PTS: 1

88. ANS: R PTS: 1

89. ANS: M PTS: 1

90. ANS: S PTS: 1

91. ANS: F PTS: 1

92. ANS: A PTS: 1

93. ANS: A PTS: 1

94. ANS: C PTS: 1

95. ANS: B PTS: 1

96. ANS: C PTS: 1

97. ANS: C PTS: 1

98. ANS: E PTS: 1

99. ANS: B PTS: 1

100. ANS: A PTS: 1

101. ANS: D PTS: 1

SHORT ANSWER

102. ANS:
Speed is defined as the distance traveled divided by the time needed to travel that distance. It is a change in position over time. Velocity takes direction into account as well as distance and time. Velocity is the distance traveled in a certain direction divided by the time it takes to travel that distance.

PTS: 1 DIF: Webb's II STA: SC.C.1.3.1

103. ANS:
Part A Newton’s first law of motion states that forces acting on an object are balanced. An object at rest tends to stay at rest and an object in motion keeps moving in a straight line with a constant speed. The net force on the object remains the same.

Part B The class can demonstrate the law by observing the car at rest and then applying a force to make the car move. However, the net force on the object will change directions because of friction acting on the car. The car will eventually slow down and stop.

PTS: 1 DIF: Webb's III STA: SC.C.2.3.5

104. ANS:
They both involve a distance, but displacement also involves a direction.

PTS: 1 DIF: Webb's II OBJ: 1/1 STA: SC.C.1.3.1

105. ANS:
Both quantities measure speed, but velocity includes direction by calculating displacement.

PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.C.1.3.1

106. ANS:
Your speed is constant. Your velocity is changing because you are changing direction. And, you are constantly accelerating because your velocity is changing.

PTS: 1 DIF: Webb's II OBJ: 2/1 STA: SC.C.1.3.1

107. ANS:
No, it is not necessary. The forces can be balanced and acting on an object that is at rest.

PTS: 1 DIF: Webb's II OBJ: 6/2 STA: SC.C.1.3.1 SC.C.2.3.3

108. ANS:
It is not true. If no forces act on a moving object, it will continue at constant velocity. It takes an unbalanced force to stop an object in motion.

PTS: 1 DIF: Webb's II OBJ: 5/2 STA: SC.C.2.3.5

109. ANS:
It would be just as hard because mass, and therefore inertia, does not change.

PTS: 1 DIF: Webb's II OBJ: 5/2 STA: SC.C.2.3.1 SC.C.2.3.2

110. ANS:
They all require a number (amount) and a direction.

PTS: 1 DIF: Webb's II OBJ: 6/2

111. ANS:
They are unbalanced. There is an unbalanced force causing acceleration.

PTS: 1 DIF: Webb's II OBJ: 6/2 STA: SC.C.1.3.1 SC.C.2.3.3

112. ANS:
There could be balanced forces acting on it.

PTS: 1 DIF: Webb's II OBJ: 6/2 STA: SC.C.1.3.1 SC.C.2.3.3 SC.C.2.3.5

113. ANS:
Possible answers: remove some of the hay from the wagon, reduce the rolling friction of the wheels.

PTS: 1 DIF: Webb's II OBJ: 10/4 STA: SC.C.2.3.3 SC.C.2.3.2

114. ANS:
The force of friction acts in opposition to motion. Therefore it is the force of friction which must be balanced in order to keep an object in motion in a constant velocity. Without friction, an object in motion at constant velocity would remain so unless acted upon by an unbalanced force.

PTS: 1 DIF: Webb's II OBJ: 10/4 STA: SC.C.2.3.5 SC.H.1.3.1

115. ANS:
black dog on rope; rope on black dog; white dog on rope; rope on white dog

PTS: 1 DIF: Webb's II OBJ: 10/4 STA: SC.C.2.3.2 SC.C.2.3.3

116. ANS:
white dog on rope; black dog on rope

PTS: 1 DIF: Webb's II OBJ: 9/3 STA: SC.C.2.3.3

117. ANS:
The rope will move in the direction of the black dog.

PTS: 1 DIF: Webb's II OBJ: 6/2 STA: SC.C.2.3.3

118. ANS:
If the black dog pulled harder on the rope.

PTS: 1 DIF: Webb's II OBJ: 6/2 STA: SC.C.2.3.3

119. ANS:
The forces on the rope are unbalanced. The white-dog-on-rope force is greater than the black-dog-on-rope force.

PTS: 1 DIF: Webb's II OBJ: 6/2 STA: SC.C.2.3.3

120. ANS:
The forces acting on the ball are hand-on-ball, gravity, and air resistance. After it leaves your hand, first it accelerates upward, then slows down, stops, and starts speeding up downward.

PTS: 1 DIF: Webb's II OBJ: 10/4 STA: SC.C.2.3.6

121. ANS:
v = d/t = 454 km/2.00 h = 227 km/h south

PTS: 1

122. ANS:
a = vf – vit = (24 m/s – 27 m/s)/6 s = –0.5 m/s2

PTS: 1

123. ANS:
F = ma = 0.14 kg ´ 100 m/s2 = 14 N

PTS: 1

124. ANS:
v = d/t = 528/6 h = 88 km/h

PTS: 1

125. ANS:
F = ma = 0.70 kg ´ 3,500 m/s2 = 2,450 N

PTS: 1

126. ANS:
Earth is so massive that the ball doesn’t accelerate it noticeably.

PTS: 1

127. ANS:
When the cars collide, each car exerts a equal but opposite force on the other car. The cars move apart in opposite directions.

PTS: 1

128. ANS:
Static friction between the desk and the carpet keeps the desk from moving.

PTS: 1

129. ANS:
It is not possible. For every action force there is a reaction force.

PTS: 1

130. ANS:
anything over 2,450 N

PTS: 1

PROBLEM

131. ANS:
s = d/t = 100 m/0.30s = 333 m/s

PTS: 1 DIF: Webb's II OBJ: 3/1 STA: SC.C.1.3.1 SC.C.1.3.2

132. ANS:
a = (vf – vl)/t = (100m/s – 0)/8 s = 12.5 m/s2

PTS: 1 DIF: Webb's II OBJ: 3/1 STA: SC.C.1.3.1

133. ANS:
a = F/m = 189 N/30 kg = 6.0 m/s2

PTS: 1 DIF: Webb's II OBJ: 7/3 STA: SC.C.2.3.7

134. ANS:
F = ma = 750 kg (4.00 m/s2) = 3,000 N

PTS: 1 DIF: Webb's II OBJ: 7/3 STA: SC.C.2.3.6

ESSAY

135. ANS:
When the astronaut exerts a clockwise force on the screwdriver, the screwdriver exerts an equal counterclockwise force on her.

PTS: 1

136. ANS:
You need to know more than just the speed. You need to know the direction the storm is traveling. You need to know not just the speed but the velocity.

PTS: 1

137. ANS:
Your displacement is zero because you are going around in a circle and end up where you started. Your velocity is not constant. You are constantly accelerating because you are constantly changing directions.

PTS: 1

138. ANS:
a. The action-reaction pairs are chain-on-wall and wall-on-chain and dog-on-chain and chain-on-dog.
b. dog-on-chain and wall-on-chain
c. The dog-on-chain force becomes greater than the wall-on-chain force and the chain moves toward the dog.

PTS: 1