Download Torque 2

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Physics 160 Torque Key
1. In the human body, most of the lever systems formed by muscles pulling on bones are what class?
a. 1st class
b. 2nd class
C. 3rd class
d. no particular class is dominant
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2. A 30 kg child sits on the right end of a see-saw 1 m from the axis. If a 20 kg child sits on the left end of the
see-saw 2 m from the axis, what will happen?
a. the see-saw will tilt to the right
B. the see-saw will tilt to the left
c. the see-saw will balance
d. need more information to predict outcome
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3. The resistance arm (RA) will always be longer than the force arm (FA) in what class lever?
a. 1st class
b. 2nd class
C. 3rd class
d. none of the classes are correct
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4. Third class lever systems favor which of the following?
a. speed
b. range of motion
c. strength
D. both speed and range of motion
e. all of the choices are correct
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5. A wheelbarrow is an example of which class of lever?
a. 1st class
B. 2nd class
c. 3rd class
d. not a lever
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6. A seesaw is an example of which class of lever?
A. 1st class
b. 2nd class
c. 3rd class
d. not a lever
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7. Which of the following will improve leverage?
a. increase force arm
b. decrease resistance arm
C. both increasing force arm and decreasing resistance arm
d. none of the choices will improve leverage
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8. A claw-tooth hammer being used to pry up a nail is an example of which class of lever?
A. 1st class
b. 2nd class
c. 3rd class
d. not a lever
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9. The relative efficiency of a lever is proportional to which of the following?
A. mechanical advantage of the lever
b. length of the force arm
c. length of the resistance arm
d. the amount of force needed to move the lever
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10. When a muscle contracts at a joint, which of the following affects torque?
A. the rotary component of muscle force
b. the stabilizing component of muscle force
c. the dislocating component of muscle force
d. none of the choices affect torque
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11. The amount of torque which must by generated by the biceps brachii at the elbow in order to maintain the
arm in a particular position is 50 Nm. If the biceps attaches to the radius at a perpendicular distance of 3 cm
from the joint center at the elbow, how much force must the muscle produce?
A. 1667 N
b. 17 N
c. 150 N
d. 1.5 N
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12. Which of the following affects the force-generating capability of a muscle?
a. the muscle length and cross-sectional area
b. the angle and distance from the joint center of the tendon attachment to bone
c. the velocity of muscle shortening
D. all of the choices affect the force-generating capability of a muscle
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13. Which of the following factors influences the amount of torque produced by muscles at a joint?
a. the amounts of tension generated by the muscles
b. the arrangement of the muscles around the joint
C. both the amounts of tension generated by the muscles and the arrangement of the muscles around the joint
d. neither the amounts of tension generated by the muscles nor the arrangement of the muscles around the joint
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14. Which of the following phrases is/are synonymous with torque?
a. moment of force
b. rotary force
c. moment arm
D. both moment of force and rotary force
e. all of the phrases are synonymous with torque
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15. Which statement is true regarding moment arm?
a. Moment arm is largest when the angle of pull on a bone is 90.
b. Changes in moment arm directly affect joint muscle torque.
c. For torque to remain constant, more force must be produced when moment arm decreases.
d. Both that the moment arm is largest when the angle of pull on a bone is 90 and that changes in moment arm
directly affect joint muscle torque
E. all of the statements are true regarding moment arm.
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16. Which of the following is/are true regarding center of mass?
a. in a spherical ball with evenly distributed mass, it is in the exact center
b. it is the point around which a body's weight is equally balanced regardless of body position
c. it may be located outside an object or body
d. the center of mass is both in a spherical ball with evenly distributed mass, it is in the exact center and it is the
point around which a body's weight is equally balanced regardless of body position
E. all of the choices are correct
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17. What is the importance of segmental center of mass to the lever systems of the human body?
a. segmental COM will follow a parabolic path when projected
B. segmental COM is the point of resistance (where weight vector is drawn) and therefore determines the length
of the resistance arm
c. segmental COM will both follow a parabolic path when projected and is the point of resistance (where weight
vector is drawn) and therefore determines the length of the resistance arm
d. none of the choices are true
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18. What will happen to the COM of a human body if the arms are raised up overhead?
A. it will move up
b. it will move down
c. it will not change
d. need more information to predict
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19. Torque is the product of force and the perpendicular distance from the force to the axis, also known as the
__________ __________.
moment arm
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20. A lever positioned with the applied resistance between the axis and the force is a __________ class lever.
second
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Category
Hall - 013 Chapter...
# of Questions
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