Deck 15: Human Movement in a Fluid Medium

Question 1

Buoyant force is directly related to what?

A) mass
B) weight
C) volume
D) density

Answer 1

volume

Question 2

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

Answer 2

all of the above

Question 3

Lift force occurs in which direction?

A) up
B) down
C) sideways
D) all of the above

Answer 3

all of the above

Question 4

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

Question 5

Which of the following is considered a fluid?

A) air
B) water
C) molasses
D) all of the above

Question 6

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

Question 7

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

Question 8

Fresh water is more dense than which of the following?

A) sea water
B) air
C) muscle
D) none of the above

Question 9

Relative velocity of the fluid affects which of the following?

A) skin friction
B) wave drag
C) lift force
D) all of the above

Question 10

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

Question 11

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

Question 12

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

Question 13

Which of the following explains buoyancy?

A) Archimedes principle
B) Bernoulli principle
C) magnus principle
D) none of the above

Question 14

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

Question 15

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

Question 16

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

Question 17

The theoretical square law is related to which of the following?

A) friction
B) lift force
C) drag
D) none of the above

Question 18

"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

Question 19

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.

Question 20

Which of the following quantities are forces?

A) friction
B) buoyancy
C) weight
D) all of the above

Question 21

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

Question 22

A man's ability to float is most directly related to his what?

A) mass
B) weight
C) volume
D) density

Question 23

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

Question 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

Question 25

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

Question 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

Question 27

Total drag is greater for which athletes?

A) swimmers
B) runners
C) equal for swimmers and runners
D) need more information

Question 28

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

Question 29

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

Question 30

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

Question 31

"Drafting" can reduce which kind of drag?

A) skin friction
B) form drag
C) wave drag
D) all of the above

Question 32

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

Question 33

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

Question 34

Which two forces are always opposite in direction?

A) lift and drag
B) buoyancy and drag
C) buoyancy and weight
D) drag and weight

Question 35

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

Question 36

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

Question 37

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

Question 38

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

Question 39

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

Question 40

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

Question 41

It is harder to float in salt water than fresh water.

Question 42

Flow that is characterized by smooth, parallel layers of fluid is called ___________________ flow.

Question 43

Explain the forces that affect flotation.

Question 44

A body will experience a greater buoyant force in salt water than fresh water because salt water has a greater ___________________.

Question 45

A buoyant force is always directed vertically upward.

Question 46

List the 3 types of drag, including the factors that affect each type.

Question 47

Explain the theoretical square law, including examples.

Question 48

Cyclists drafting will minimize form drag.

Question 49

A lift force created by spin is called ___________________ force.

Question 50

Explain the Bernoulli principle.

Question 51

Examples of fluids that exert forces on the human body are ___________________ and ___________________.

Question 52

The physical law stating that the buoyant force acting on a body is equal to the weight of the fluid displaced by the body is called ___________________ ___________________.

Question 53

If weight is equal to buoyant force, a body will sink.

Question 54

Discuss the Magnus effect, providing examples.

Question 55

The Bernoulli Principle explains the inverse relationship between velocity and pressure.