Chapter 4 Machines & Mechanical Systems
Multiple Choice
Identify the choice that best completes the statement or answers the question.
1.
What mass must be placed on the above lever in order to have an equalibrium?
A. 1 kg
B. 2 kg
C. 3 kg
D. 4 kg
E. 6 kg
2.
The lever in the picutre will:
A. rotate clockwise.
B. rotate counterclockwise.
C. stay balanced.
D. rotate clockwise, until the forces become equal.
E. rotate counterclockwise, until the forces become equal.
3. The ___ is the force applied by a machine to accomplish a task after an input force has been applied.
A. input arm
B. input force
C. newton
D. output arm
E. output force
5.
Which of the above levers has the greatest mechanical advantage?
A. diagram A
B. diagram B
C. diagram C
D. All diagrams have the same mechanical advantage.
E. Without futher information the relative mechanical advantages cannot be determined.
6.
The lever in the picutre will:
A. rotate clockwise.
B. rotate counterclockwise.
C. stay balanced.
D. rotate clockwise, until the forces become equal.
E. rotate counterclockwise, until the forces become equal.
9. A(n) ___ is a pivot point of a lever.
A. fulcrum
B. input force
C. lever
D. machine
E. mechanical system
10. A(n) ___ is an object with interrelated parts that work together to accomplish a task.
A. fulcrum
B. input force
C. lever
D. machine
E. mechanical system
12. Which of the following is NOT considered a simple machine?
A. wheel and axle
B. electric motor
C. lever
D. block and tackle
E. inclined plane
16. Which of the following block and tackle systems has the largest mechanical advantage?
A.
B.
C.
D.
E.
System A has the largest mechanical advantage.
System B has the largest mechanical advantage.
System C has the largest mechanical advantage.
All three systems have the same mechanical advantage.
Without further information the mechanical advantage cannot be determined.
17. The ___ is the distance from the fulcrum to the point of input force.
A. input arm
B. input force
C. lever
D. output arm
E. output force
18. The ___ is the distance from the fulcrum to the point of output force.
A. input arm
B. input force
C. lever
D. output arm
E. output force
19. The ___ is the force applied to a machine.
A. input arm
B. input force
C. newton
D. output arm
E. output force
20. A(n) ___ is a simple machine that pivots around a fulcrum.
A. fulcrum
B. input force
C. lever
D. machine
E. mechanical system
21. What are the units for mechanical advantage?
A.
B.
C.
D.
E.
meters
meters per second
newtons
newtons per second
There are no units.
22. What would be the proper combination of weights below to balance the following lever?
A.
B.
C.
D.
E.
0,0,1  0,0,1
0,1,4 2,3,0
9,0,6  30,4,0
3,4,3  0,2,1
4,0,1  3,5,0
23. The human arm is an example of which class of lever?
A.
B.
C.
D.
E.
first class
second class
third class
fourth class
None of the above.
24. A simple machine often multiplies your
A. distance
B. energy
C. force
D. power
E. work
25. A(n) ___ is a device that multiplies force.
A.
B.
C.
D.
E.
fulcrum
input force
lever
machine
mechanical system
26. Which of the following is NOT considered a simple machine?
A. Wheel and axle
B. Electric motor
C. Lever
D. Rope and pulley
27. In a machine, work output:
A. can be calculated by dividing output distance by output force.
B. is always greater than the work input.
C. can be calculated by multiplying output force by output distance.
D. is always equal to the work input.
28. What is required to get work out of a machine?
A. Friction
B. Efficiency
C. Input work
D. Gears
29. A lever rotates around a fixed point called a:
A. ball bearing.
B. gear.
C. pulley.
D. fulcrum.
30. The simple machine that operates as a ramp that curves around a shaft is a:
A. rope and pulley system.
B. screw.
C. lever.
D. gear.
31. The force directed along the ropes of a rope and pulley system is called:
A. thread.
B. lead.
C. mechanical advantage.
D. tension.
Figure 9-1A
32. In the picture of the crowbar, which letter shows the fulcrum?
A. A
B. B
C. C
D. None of the above
33. In the picture of the crowbar, which letter shows the input force?
A. A
B. B
C. C
D. None of the above
34. The gear ratio is equal to:
A. output teeth divided by input teeth.
B. output turns divided by input turns.
C. input speed divided by output speed.
D. input direction divided by output direction.
Figure 9-1
35. According to Figure 9-1, if the output force of a lever is located between the fulcrum and input force, the
lever is a:
A. first class lever.
B. second class lever.
C. third class lever.
D. Not enough information is given.
36. In which class of levers shown in Figure 9-1 is mechanical advantage always greater than 1?
A. First class
B. Second class
C. Third class
D. You cannot have a mechanical advantage greater than 1.
37. The human arm is an example of which class of lever?
A.
B.
C.
D.
First class
Second class
Third class
None of the above
38. Which of the following rope and pulley systems has the largest mechanical advantage?
A.
B.
C.
D.
System A has the largest mechanical advantage.
System B has the largest mechanical advantage.
System C has the largest mechanical advantage.
All three systems have the same mechanical advantage.
44. All of the following simple machines are represented in the diagram below EXCEPT:
A.
B.
C.
D.
lever.
ramp.
wheel and axle.
rope and pulley.
45. Janice experiments with two meshed gears. She observes that when she rotates the input gear 5 times, the
output gear rotates 15 times. What is the gear ratio of this system?
A. 3:1
B. 2:1
C. 15:1
D. 4:1
46. If the output force is bigger than the input force, the mechanical advantage is always:
A. between 0 and 1.
B. less than 1.
C. larger than 1.
D. 0.
47. Making a ramp steeper:
A. increases its mechanical advantage.
B. decreases its mechanical advantage.
C. increases its efficiency.
D. decreases its efficiency.
48. What are the units of mechanical advantage?
A. Newtons
B. Joules
C. Watts
D. Mechanical advantage has no units.
49. On a 10-speed bicycle, gears increase the mechanical advantage of the bicycle. In which of the following
situations would you want the greatest mechanical advantage for the gear system?
A. Climbing up a hill
B. Coasting down a hill
C. Riding on level ground
D. Stopping suddenly to avoid a crash
50. When a perfect machine that multiplies force is used:
A. the input work must be less than the output work.
B. the input force must be greater than the output force.
C. the input distance must be greater than the output distance.
D. the output power must be greater than the input power.
51. In the human body, what does the elbow joint act as?
A. Fulcrum
B. Gear
C. Ramp
D. Screw
52. When you stand on your toes, what does your foot act as?
A. Gear
B. Lever
C. Screw
D. Ramp
Chapter 4 Machines & Mechanical Systems
Answer Section
MULTIPLE CHOICE
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48.
ANS: C
ANS: A
ANS: E
REF: vocab
ANS: A
ANS: B
ANS: A
ANS: E
REF: vocab
REF: vocab
ANS: B
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C
A
D
B
C
E
E
C
C
D
B
C
C
D
B
D
C
B
B
B
B
C
C
ANS:
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A
C
B
D
REF:
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vocab
vocab
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vocab
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vocab
section 9.1
section 9.1
section 9.1
section 9.1
section 9.2
section 9.2
section 9.2
section 9.2
section 9.2
section 9.2
section 9.2
section 9.2
section 9.2
REF:
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REF:
section 9.2
section 9.2
section 9.2
section 9.2
49.
50.
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52.
ANS:
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A
C
A
B
REF:
REF:
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section 9.2
section 9.2
section 9.3
section 9.3