Chapter 8 Quiz

Question 1

Match the linear term, impulse (Ft), to its angular analogue.

Question options:

1) Iω

2) Iα

3) Moment of inertia

4) Torque

Answer 1

Iω

Question 2

Why does gravity not affect angular momentum?

Question options:

1) Gravity does affect angular momentum.

2) Both d⊥ = 0 and T = 0

3) d⊥ = 0

4) T = 0

Answer 2

Both d⊥ = 0 and T = 0

Question 3

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?

Question options:

1) Newton’s first law of inertia

2) Newton’s second law of acceleration

3) Newton’s third law of action/reaction

4) None of the above

Answer 3

Newton’s first law of inertia

Question 4

Somersaulting occurs around which of the following axes of rotation?

Question options:

1) Frontal

2) Longitudinal

3) Sagittal

4) All of the above

Answer 4

Frontal

Question 5

Why does a figure skater cross his arms tightly across the chest when performing a quadruple axel?

Question options:

1) To reduce moment of inertia

2) To increase angular velocity

3) To increase time in the air

4) Both A and B

5) All of the above

Answer 5

Both A and B

Question 6

When a cyclist rounds a curve, where does centripetal force act?

Question options:

1) On the cyclist’s centre of gravity

2) On the tires of the cycle

3) On the ground

4) On the cycle’s centre of gravity

Answer 6

On the tires of the cycle

Question 7

Moment of inertia is the angular analogue of which of the following?

Question options:

1) Moment of force

2) Moment of time

3) Mass

4) Surface area

Answer 7

Mass

Question 8

Match the linear term, momentum (M = mv), to its angular analogue.

Question options:

1) Moment of inertia

2) Torque

3) Iω

4) Iα

Answer 8

Iω

Question 9

Rotating around which of the following principal axes of rotation has the least moment of inertia (anatomical position)?

Question options:

1) Anteroposterior (sagittal)

2) Longitudinal

3) Transverse (frontal)

4) Need more information

Answer 9

Longitudinal

Question 10

Regarding moment of inertia of the leg with respect to the hip, which of the following leg morphologies would favor a sprinter?

Question options:

1) Massive thighs and slimmer lower legs

2) Massive lower legs and slimmer thighs

3) Need more information

4) Leg morphology does not matter

Answer 10

Massive thighs and slimmer lower legs

Question 11

Which of the following is/are accurate formula(s) for angular momentum?

Question options:

1) H = Iω

2) H = mk2ω

3) M = mv

4) Both H = Iω and H = mk2ω

Answer 11

Both H = Iω and H = mk2ω

Question 12

What are the appropriate units for angular momentum?

Question options:

1) kg·m/s2

2) kg·m2/s

3) kg2·m/s

4) kg·m2

Answer 12

kg·m2/s

Question 13

Why do sprint coaches stress “heel to buttocks” during sprinting?

Question options:

1) Reduces moment of inertia of the foot with respect to the ankle

2) There is no scientific basis for this coaching cue.

3) Reduces moment of inertia of the lower leg with respect to the knee

4) Reduces moment of inertia of the leg with respect to the hip

Answer 13

Reduces moment of inertia of the leg with respect to the hip

Question 14

What will happen to angular velocity when a diver goes from a tuck position to a full layout position?

Question options:

1) Remain the same

2) Decrease

3) Need more information

4) Increase

Answer 14

Decrease

Question 15

What will happen to angular momentum when a diver goes from a tuck position to a full layout position?

Question options:

1) Decrease

2) Increase

3) Remain the same

4) Need more information

Answer 15

Remain the same

Question 16

Which of the following are accurate units for moment of inertia?

Question options:

1) kg·m

2) N·m

3) N·m2

4) kg·m2

Answer 16

kg·m2

Question 17

If a pendulum stops swinging, which of the following is/are true?

Question options:

1) Angular velocity = 0

2) Angular momentum = 0

3) Both angular velocity and angular momentum equal 0

4) None of the choices is true.

Answer 17

Both angular velocity and angular momentum equal 0

Question 18

Centripetal force is related to which of the following?

Question options:

1) Radial acceleration

2) Tangential acceleration

3) Both A and B

4) None of the choices is correct.

Answer 18

Radial acceleration

Question 19

When knee flexion is increased, what happens to the moment of inertia of the leg about the hip?

Question options:

1) Decreased

2) Need more information

3) Increased

4) Remains the same

Answer 19

Decreased

Question 20

Which of the following are accurate units for centripetal force?

Question options:

1) N

2) N-kg·m

3) kg·m2/s

4) kg·deg2/s

Answer 20

N

Question 21

Which of the following acts to produce a change in angular momentum?

Question options:

1) Angular impulse

2) Moment of inertia

3) Torque

4) None of the choices is correct.

Answer 21

Angular impulse

Question 22

Which of the following quantities increases as moment of inertia decreases during the airborne phase of a dive?

Question options:

1) Angular momentum

2) Angular velocity

3) Both A and B

4) Neither A or B

Answer 22

Angular velocity

Question 23

If a diver goes from a full layout position to a tuck position, what will happen to his momentum?

Question options:

1) Decrease

2) Increase

3) Need more information

4) Remain the same

Answer 23

Remain the same

Question 24

Centrifugal force is a misnomer. What is really happening when you feel a pull to the outside while rounding a curve?

Question options:

1) Centripetal force

2) Inertia

3) Both centripetal force and inertia

4) None of the choices is correct.

Answer 24

Inertia

Question 25

How many principle axes are there for the human body? Question options: 1) One 2) Two 3) Three 4) Four

Answer 25

Three

Question 26

Which of the following is/are most important factor(s) affecting the magnitude of centripetal force? Question options: 1) Mass 2) Radius of rotation 3) Tangential linear velocity 4) All of the above

Answer 26

Tangential linear velocity

Question 27

Which of the following variables contribute to moment of inertia? Question options: 1) T and t 2) m and k 3) F and d 4) M and v

Answer 27

m and k

Question 28

How can a cyclist maintain balance when rounding a sharp curve? Question options: 1) Slow down 2) Lean to the inside of the curve 3) Lean to the outside of the curve 4) Both A and B

Answer 28

Both A and B

Question 29

Which of the following variables affects angular momentum? Question options: 1) Linear velocity 2) Angular acceleration 3) Both linear velocity and angular acceleration 4) Neither linear velocity nor angular acceleration

Answer 29

Neither linear velocity nor angular acceleration

Question 30

According to Newton's 2nd Law, what is the relationship among torque, moment of inertia, and angular acceleration? Question options: 1) T = Iω 2) I = Tα 3) α = TI 4) T = Iα

Answer 30

T = Iα

Question 31

In the absence of external torque, which of the following will increase when moment of inertia decreases? Question options: 1) Angular momentum 2) Angular velocity 3) Both angular momentum and angular velocity 4) None of the choices will increase when moment of inertia decreases

Answer 31

Angular velocity

Question 32

Which of the following best describes the centripetal forces experienced by a baserunner weighing 70 Newtons and a baserunner weighing 50 Newtons? Question options: 1) The centripetal force exerted on the heavier baserunner will be greater. 2) The heavier baserunner will not be able to run as fast around the bases due to a greater centripetal force. 3) 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. 4) All of the choices are true.

Answer 32

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.

Question 33

When a discus thrower spins and then releases the discus, what direction will it travel? Question options: 1) Will continue in circular path 2) Tangent to the circular path at beginning of spin 3) Tangent to the circular path at release 4) Need more information

Answer 33

Tangent to the circular path at release

Question 34

Where is radius of gyration located in relation to centre of gravity (COG)? Question options: 1) Need more information 2) Same distance from the axis 3) Closer to the axis 4) Further from the axis

Answer 34

Further from the axis

Question 35

Which of the following accurately describes the radius of gyration of the forearm segment? Question options: 1) It is greater with respect to the wrist than with respect to the elbow. 2) Need more information 3) It is greater with respect to the elbow than with respect to the wrist. 4) It is equal with respect to the wrist and with respect to the elbow.

Answer 35

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

Question 36

Why are golf club heads weighted? Question options: 1) To decrease the moment of inertia of the club with respect to the shoulder 2) To increase the moment of inertia of the club head rotating around the shaft 3) To decrease the moment of inertia of the club head rotating around the shaft 4) To increase the moment of inertia of the club with respect to the shoulder

Answer 36

To increase the moment of inertia of the club head rotating around the shaft