Chapter 15

34. Which of the following is considered a foil shape? A. human hand B. discus C. shot put D. both A and B E. all of the above

D. both A and B

39. Golf clubs are designed to impart backspin, which affects the ball in what way? A. increase in flight time B. increase in range C. both A and B D. none of the above

C. both A and B

27. Which two forces are always opposite in direction? A. lift and drag B. buoyancy and drag C. buoyancy and weight D. drag and weight

C. buoyancy and weight

22. Which of the following is defined "velocity of a body with respect to the velocity of the wind (or other surrounding fluid)"? A. resultant velocity B. absolute velocity C. relative velocity D. all of the above

C. relative velocity

12. Which of the following quantities affects a discus as it travels through the air? A. surface drag B. lift force C. both A and B D. neither A nor B

C. Both A and B

18. Which of the following explains buoyancy? A. Archimedes principle B. Bernoulli principle C. magnus principle D. none of the above

A. Archimedes principle

32. How do dimples on a golf ball reduce form drag? A. produce a turbulent boundary layer B. produce a laminar boundary layer C. both A and B D. dimples do not reduce form drag

A. produce a turbulent boundary layer

29. Total drag is greater for which athletes? A. swimmers B. runners C. equal for swimmers and runners D. need more information

A. swimmers

16. The theory attributing propulsion in swimming to Newton's third law is what? A. the propulsive drag theory B. the propulsive lift theory C. the vortex theory D. none of the above

A. The propulsive drag theory

17. The inverse relationship between relative velocity and relative pressure in a fluid is what? A. Archimedes principle B. Bernoulli principle C. magnus principle D. none of the above

B. Bernoulli principle

19. Fresh water is more dense than which of the following? A. sea water B. air C. muscle D. none of the above

B. air

26. For flotation to occur, which of the following must exist? A. buoyant force must exceed weight B. buoyant force must equal or exceed weight C. weight must exceed buoyant force D. weight must equal or exceed buoyant force

B. buoyant force must equal or exceed weight

25. Which of the following statements is always true? A. center of volume is in the same place as center of mass B. center of volume is in the same place as center of buoyancy C. center of mass is in the same place as center of buoyancy D. all of the above are true

B. center of volume is in the same place as center of buoyancy

24. Which of the following are inversely related? A. density and volume B. density and specific weight C. specific weight and mass D. mass and density

B. density and specific weight

33. "Drafting" can reduce which kind of drag? A. skin friction B. form drag C. wave drag D. all of the above

B. form drag

28. Why were so many world records set at the 1968 Olympic Games in Mexico City? A. higher altitude reduced VO2max B. higher altitude reduced drag force C. both A and B D. none of the above

B. higher altitude reduced drag force

35. Ski jumpers attempt to do which of the following? A. increase lift and increase drag B. increase lift and decrease drag C. decrease lift and decrease drag D. decrease lift and increase drag

B. increase lift and decrease drag

40. Which of the following acts in the same direction as body motion? A. wave drag B. propulsive drag C. skin friction D. all of the above

B. propulsive drag

38. A curve ball pitch follows which path? A. straight line with sudden break at the end B. smooth arc C. can be either A or B D. none of the above

B. smooth arc

23. Which of the following statements is accurate? A. As a fluid becomes denser, it exerts greater forces on moving body. B. As a fluid becomes denser, it becomes more viscous. C. both A and B D. none of the above

C. both A and B

15. Which of the following statements is true of the Magnus force? A. It is created by spin on a ball. B. It is created by a pressure differential. C. Both A and B are true. D. Neither A nor B is true.

C. Both A and B are true

3. "A flow characterized by smooth, parallel layers of fluid" is the definition of which of the following? A. relative velocity B. turbulent flow C. laminar flow D. none of the above

C. Laminar flow

Buoyant force is directly related to what? A. mass B. weight C. volume D. density

C. Volume

13. Which type of fluid resistance is likely to be greatest on a swimmer in the ocean at a fast speed? A. skin friction B. profile drag C. wave drag D. none of the above

C. Wave Drag

8. The nature of the boundary layer depends on which of the following? A. the roughness of the body's surface B. the body's velocity relative to flow C. both A and B D. none of the above

C. both A and B

5. The theoretical square law is related to which of the following? A. friction B. lift force C. drag D. none of the above

C. drag

20. Which of the following is considered a fluid? A. air B. water C. molasses D. all of the above

D. all of the above

30. Which of the following is true regarding passive drag? A. generated by a swimmer's body size, shape, and position in the water B. inversely related to a swimmer's buoyancy C. associated with the swimmer in motion D. both A and B E. all of the above

D. both A and B

31. Which of the following factors that affect skin drag, can athletes usually alter? A. roughness of the body surface B. amount of surface area in contact with the fluid C. viscosity of the fluid D. both A and B E. all of the above

D. both A and B

36. Which of the following statements is/are true? A. Angle of attack and release angle both affect horizontal range. B. Angle of attack and release angle are independent of each other. C. Angle of attack and release angle are always equal. D. both A and B E. all of the above

D. both A and B

21. A man's ability to float is most directly related to his what? A. mass B. weight C. volume D. density

D. density

2. Which of the following quantities are forces? A. friction B. buoyancy C. weight D. all of the above

D. All of the above

4. Which of the following is not true about drag? A. it is a force caused by the action of a fluid B. it is affected by surface area C. it is affected by the density of the fluid D. all of the above are true

D. All of the above

6. Which of the following factors affects skin friction drag? A. increase in the relative velocity of fluid flow B. the surface area of the body over which the flow occurs C. the viscosity of the fluid D. all of the above

D. All of the above

7. Which of the following describes the drag created by a pressure differential between the lead and rear sides of a body moving through a fluid? A. form drag B. profile drag C. surface drag D. both A and B above

D. Both A and B above

9. Which of the following terms describes a force acting on a body in a fluid in a direction perpendicular to the fluid flow? A. wave drag B. surface drag C. form drag D. lift

D. Lift

10. Which of the following factors affects lift force? A. relative velocity of the fluid B. fluid density C. size, shape, and orientation of the body D. all of the above

D. all of the above

11. Lift force occurs in which direction? A. up B. down C. sideways D. all of the above

D. all of the above

14. Relative velocity of the fluid affects which of the following? A. skin friction B. wave drag C. lift force D. all of the above

D. all of the above

37. Topspin on a tennis ball will have what effect? A. Ball will drop sooner. B. Ball will rebound lower. C. Ball will rebound faster. D. both A and B E. all of the above

E. all of the above