Chapter 14

23. Which of the following accurately describes the radius of gyration of the forearm segment? A. It is greater with respect to the wrist than with respect to the elbow. B. It is greater with respect to the elbow than with respect to the wrist. C. It is equal with respect to the wrist and with respect to the elbow. D. need more information

A. It is greater with respect to the wrist than with respect to the elbow.

15. The statement "a rotating body will maintain a state of constant angular motion unless acted on by an external torque" refers to which of the following? A. Newton's first law of inertia B. Newton's second law of acceleration C. Newton's third law of action/reaction D. none of the above

A. Newton's first law of inertia

32. According to Newton's 2nd Law, what is the relationship among torque, moment of inertia, and angular acceleration? A. T = Iα B. I = Tα C. α = TI D. T = Iω

A. T = Iα

30. If total body angular momentum is 0, what will happen as the result of a forceful movement such as a spike? A. compensatory rotation in lower body in opposite direction B. compensatory rotation in upper body called follow-through C. angular momentum is no longer 0 D. all of the above

A. compensatory rotation in lower body in opposite direction

10. Somersaulting occurs around which of the following axes of rotation? A. frontal B. sagittal C. longitudinal D. all of the above

A. frontal

7. If a diver goes from a full layout position to a tuck position, what will happen to her angular velocity? A. increase B. decrease C. remain the same D. need more information

A. increase

28. What are the appropriate units for angular momentum? A. kg•m2/s B. kg•m/s2 C. kg2•m/s D. kg•m2

A. kg•m2/s

22. Regarding moment of inertia of the leg with respect to the hip, which of the following leg morphologies would favor a sprinter? A. massive thighs and slimmer lower legs B. massive lower legs and slimmer thighs C. leg morphology does not matter D. need more information

A. massive thighs and slimmer lower legs

16. Centripetal force is related to which of the following? A. radial acceleration B. tangential acceleration C. both A and B D. none of the above

A. radial acceleration

38. Why do sprint coaches stress "heel to buttocks" during sprinting? A. reduces moment of inertia of the leg with respect to the hip B. reduces moment of inertia of the lower leg with respect to the knee C. reduces moment of inertia of the foot with respect to the ankle D. there is no scientific basis for this coaching cue

A. reduces moment of inertia of the leg with respect to the hip

37. When a discus thrower spins and then releases the discus, what direction will it travel? A. tangent to the circular path at release B. tangent to the circular path at beginning of spin C. will continue in circular path D. need more information

A. tangent to the circular path at release

34. Which of the following is/are most important factor(s) affecting the magnitude of centripetal force? A. tangential linear velocity B. radius of rotation C. mass D. all of the above are equally important

A. tangential linear velocity

39. Why is a bat easier to swing if you grip the barrel instead of the handle? A. k is reduced B. k is increased C. moment of inertia is increased D. easier to grip the barrel

A. k is reduced

13. Which of the following quantities increases as moment of inertia decreases during the airborne phase of a dive? A. angular momentum B. angular velocity C. both A and B D. neither A nor B

B. angular velocity

6. Where is radius of gyration located in relation to center of gravity (COG)? A. closer to the axis B. further from the axis C. same distance from the axis D. need more information

B. further from the axis

20. Centrifugal force is a misnomer. What is really happening when you feel a pull to the outside while rounding a curve? A. centripetal force B. inertia C. both A and B D. none of the above

B. inertia

40. Why are golf club heads weighted? A. to increase the moment of inertia of the club with respect to the shoulder B. to increase the moment of inertia of the club head rotating around the shaft C. to decrease the moment of inertia of the club with respect to the shoulder D. to decrease the moment of inertia of the club head rotating around the shaft

B. to increase the moment of inertia of the club head rotating around the shaft

3. In the absence of external torque, which of the following will increase when moment of inertia decreases? A. angular momentum B. angular velocity C. both A & B D. none of the above

B. Angular Velocity

2. When knee flexion is increased, what happens to the moment of inertia of the leg about the hip? A. increased B. decreased C. remains the same D. need more information

B. Increased

33. Which of Newton's laws (angular analogues) explains why a batter wears cleats? A. 1st law - moment of inertia B. 2nd law - angular acceleration C. 3rd law - reaction D. none of the above

C. 3rd law - reaction

14. Which of the following acts to produce a change in angular momentum? A. moment of inertia B. torque C. angular impulse D. none of the above

C. angular impulse

27. If a pendulum stops swinging, which of the following is/are true? A. angular velocity = 0 B. angular momentum = 0 C. both A and B D. none of the above

C. both A and B

29. How come gravity does not affect angular momentum? A. d⊥ = 0 B. T = 0 C. both A and B D. gravity does affect angular momentum

C. both A and B

18. Which of the following is true of a baserunner weighing 70 Newtons and a baserunner weighing 50 Newtons? A. the centripetal force exerted on the heavier baserunner will be greater B. the heavier baserunner will not be able to run as fast around the bases, due to a greater centripetal force C. if the baserunners run at the same velocity around the bases, the heavier baserunner will have to lean in more towards the pitcher's mound due to a greater centripetal force D. all of the above are true

C. if the baserunners run at the same velocity around the bases, the heavier baserunner will have to lean in more towards the pitcher's mound due to a greater centripetal force

24. Which of the following are accurate units for moment of inertia? A. N•m B. N•m2 C. kg•m2 D. kg•m

C. kg•m2

25. Rotating around which of the following principal axes of rotation has the least moment of inertia (anatomical position)? A. transverse (frontal) B. anteroposterior (sagittal) C. longitudinal D. need more information

C. longitudinal

19. When a cyclist rounds a curve, where does centripetal force act? A. on the cyclist's center of gravity B. on the cycle's center of gravity C. on the tires of the cycle D. on the ground

C. on the tires of the cycle

8. If a diver goes from a full layout position to a tuck position, what will happen to his momentum? A. increase B. decrease C. remain the same D. need more information

C. remain the same

36. Which of the following are accurate units for centripetal force? A. kg•m2/s B. kg•deg2/s C. N D. N-kg•m

C. N

1.Moment of inertia is the angular analogue of what? A. moment of force B. moment of time C. mass D. surface area

C. mass

12. Which of the following is referred to as the "quantity of angular motion" possessed by a body? A. angular displacement B. angular velocity C. angular acceleration D. angular momentum

D. angular momentum

21. What effect does "choking up" on a bat have? A. reduces moment of inertia B. increases angular velocity of swing C. reduces mass D. both A and B E. all of the above

D. both A and B

26. Which of the following is/are accurate formula(s) for angular momentum? A. H = Iω B. H = mk2ω C. M = mv D. both A and B E. all of the above

D. both A and B

31. Why does a figure skater cross his arms tightly across the chest when performing a quadruple axel? A. to reduce moment of inertia B. to increase angular velocity C. to increase time in the air D. both A and B E. all of the above

D. both A and B

35. How can a cyclist maintain balance when rounding a sharp curve? A. slow down B. lean to the inside of the curve C. lean to the outside of the curve D. both A and B E. none of the above will affect balance

D. both A and B

11. Which of the following variables affects angular momentum? A. linear velocity B. angular acceleration C. both A and B D. neither A nor B

D. neither A nor B

4. Torque is the angular analogue of what? A. momentum B. force C. mass D. impulse

B. Force

9. How many principle axes are there for the human body? A. one B. two C. three D. four

C. three

17. Which of the following is known as "center-seeking" force? A. momentum B. acceleration C. centrifugal force D. centripetal force

D. centripetal force

5. Which of the following variables contribute to moment of inertia? A. F and d B. T and t C. M and v D. m and k

D. m and k