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Name: ________________________ Class: ___________________ Date: __________
ID: A
Chapter 09 Multi-format Test
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. In a perfect machine, the output work exactly equals the input work. _________________________
____
2. The work a machine does for you is called the input work. _________________________
____
3. The fixed point around which a lever rotates is called the arm of the lever. _________________________
____
4. In a rope and pulley system, the number of strands supporting the load equals the mechanical advantage.
_________________________
____
5. The human body is a complex machine made up of simple machines including levers.
_________________________
Completion
Complete each statement.
Select the correct term to complete each sentence. There are extra terms in the list.
lever
output arm
simple machine
more
force
gear
fulcrum
input
less
distance
input arm
complex machine
output
mechanical advantage
tension
6. Ramps, levers, wheels and axles, and gears are all examples of ____________________.
7. The force, energy, or power supplied to make a machine work is called ____________________.
8. A(n) ____________________ is a rotating wheel with teeth that transfers motion and forces.
9. To achieve a mechanical advantage of more than one, force is traded for ____________________.
10. If the output gear turns faster than the input gear, it will turn with ____________________ force.
11. The ratio of the output force to the input force is called ____________________.
12. The pulling force that always acts along the direction of the rope in a pulley system is called
____________________.
Matching
Match each example with the type of simple machine that best describes it. The simple machines may be used
more than once.
a. rope and pulleys
c. lever
b. wheel and axle
d. wedge
____ 13. an axe
____ 14. block and tackle used to raise the sail on a boat
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____
____
____
____
____
____
15.
16.
17.
18.
19.
20.
ID: A
tires on a car
baseball bat
scissors
door on hinges
door knob
your arms
Short Answer
21. Chris uses a lever to pry off the top of a can of paint. Describe the source of the input energy to the lever?
22. Name the three basic parts of a lever.
23.
Using the table above, name an example for each of the three classes of levers.
24. There are three ropes supporting the load in a rope and pulley system. What is the relationship between the
tension in each supporting rope and the input force applied to the system?
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ID: A
Problem
25. A construction worker uses a rope and pulley to lift 2,400 newtons of lumber from the ground to a waiting
helper on the second floor, 4 meters from the ground. To do this, she applies a 250-newton force on the rope
of the rope and pulley. She pulls 50 meters of rope through the rope and pulley before the load is lifted to the
second floor. Based upon the information given, calculate the following for this rope and pulley:
a. work input
b. work output
c. efficiency
26. A ramp 20 meters long is used to raise a 400 newton cart 2 meters. If the ramp and cart are 100% efficient,
what is the mechanical advantage of the ramp system?
27. Study the gears shown below. How many teeth are there on the gear that turns 24 times?
28. The picture shows the foot acting as a second class lever.Using the distances shown in the picture, calculate
the foot’s mechanical advantage.
Essay
29. Explain what is meant when the statement is made that energy is conserved by a machine.
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Other
30. Study the wheelbarrow picture. The arrows in the drawing represent the input force, the output force, and the
fulcrum.
a. Write the words input force, output force, and fulcrum next to the correct arrow to identify what each
arrow represents.
b. Identify the wheelbarrow as a first, second, or third class lever.
c. Tell why you have identified the wheelbarrow as this class of lever.
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ID: A
Chapter 09 Multi-format Test
Answer Section
MODIFIED TRUE/FALSE
1. ANS: T
2. ANS: F, output
DIF: basic
3. ANS: F, fulcrum
REF: section 9.1
DIF: basic
4. ANS: T
5. ANS: T
REF: section 9.1
DIF: basic
REF: section 9.1
DIF: basic
DIF: basic
REF: section 9.2
REF: section 9.3
COMPLETION
6. ANS: simple machines
DIF: basic
7. ANS: input
REF: section 9.1
STA: S8CS5a
DIF: basic
8. ANS: gear
REF: section 9.1
STA: S8P3c
DIF: basic
9. ANS: distance
REF: section 9.1
DIF: basic
10. ANS: less
REF: section 9.2
DIF: intermediate REF: section 9.2
11. ANS: mechanical advantage
DIF: basic
12. ANS: tension
DIF:
REF: section 9.2
basic
REF: section 9.2
D
A
B
C
C
DIF:
DIF:
DIF:
DIF:
DIF:
MATCHING
13.
14.
15.
16.
17.
ANS:
ANS:
ANS:
ANS:
ANS:
basic
basic
basic
basic
basic
REF:
REF:
REF:
REF:
REF:
1
section 9.2
section 9.2
section 9.2
section 9.2
section 9.2
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ID: A
18. ANS: C
19. ANS: B
20. ANS: C
DIF: basic
DIF: basic
DIF: basic
REF: section 9.2
REF: section 9.2
REF: section 9.3
SHORT ANSWER
21. ANS:
The input energy to the lever is supplied by Chris. It is transferred from Chris’s muscles to the lever in order
to get useful work out of the lever.
DIF: basic
REF: section 9.1
22. ANS:
input arm, output arm, and fulcrum
DIF: basic
REF: section 9.1
STA: S8P3c
23. ANS:
Answers will vary. Correct answers include:
first class: seesaw, pliers, scissors, can opener (punches hole in can top)
second class: door, wheel barrow, book cover, bottle cap remover
third class: arms or legs of the human body, fishing pole, hammer to pound nails, baseball bat
DIF: intermediate REF: section 9.2
24. ANS:
The tension in each rope is the same as the force applied to the system.
DIF:
intermediate
REF: section 9.2
PROBLEM
25. ANS:
a.
work input = force × distance
work input = 250 newtons × 50 meters
work input = 12,500 joules
b.
work output = force × distance
work output = 2,400 newtons × 4 meters
work output = 9,600 joules
c
efficiency = work output ÷ work input
efficiency = 9,600 joules ÷ 12,500 joules
efficiency = 77%
DIF:
intermediate
REF: section 9.1
2
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ID: A
26. ANS:
mechanical advantage =
ramp length
ramp height
mechanical advantage =
20 m
2m
mechanical advantage = 10
DIF: intermediate REF: section 9.2
STA: S8CS3f
27. ANS:
The gear has 18 teeth.
turns of output gear number of teeth in output gear
=
turns of input gear
number of teeth in input gear
12 turns number of teeth in input gear
=
36 teeth
24 turns
number of teeth of input gear =
12 turns × 36 teeth
24 turns
number of teeth of input gear = 18 teeth
DIF: intermediate
28. ANS:
REF: section 9.2
mechanical advantage =
length of input arm
length of output arm
mechanical advantage =
20
=5
5
DIF:
intermediate
REF: section 9.3
ESSAY
29. ANS:
As the machine operates, energy is used in the operation of the machine to perform a certain task. The amount
of work done in performing the task (plus any energy "lost" as heat due to friction) equals the amount of
energy input - the energy used to operate the machine as the work is being done.
DIF:
intermediate
REF: section 9.1
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OTHER
30. ANS:
a. fulcrum at the wheel, output force at the load, input force at the handle
b. second class
c. the load/output force is located between the fulcrum and input force
DIF:
advanced
REF: section 9.2
STA: S8P3c
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Chapter 09 Multi-format Test [Answer Strip]
T
_____
1.
F
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2.
F
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3.
T
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4.
T
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5.
D 13.
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A 14.
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B
_____
C
_____
C
_____
C
_____
B
_____
C
_____
15.
16.
17.
18.
19.
20.
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ID: A