Chapter 6 - Angular Kinetics

Question 1

Explain Newton’s first law of motion as it applies to angular motion

Answer 1

The angular momentum of an object remains constant unless acted on by an external torque
Even though angular momentum is constant, angular velocity can change due to changes in moment of inertia
“Conservation of Angular Momentum”

Question 2

Explain Newton’s second law of motion as it applies to angular motion

Answer 2

(F=ma)
A net torque produces angular acceleration of a body that is proportional to the magnitude of the torque, in the same directions as the torque, and inversely proportional to the moment of inertia
T=Iα

Question 3

Explain Newton’s third law of motion as it applies to angular motion

Answer 3

For every torque exerted by one body on another, the other body exerts an equal torque back on the first body but in the opposite direction

Question 4

Define moment of inertia

Answer 4

Moment of Inertia (MOI) is angular inertia

Question 5

Explain how the human body’s moment of inertia may be manipulated

Answer 5

Since humans can move their limbs, the distribution of mass of the body will change, therefore the moment of inertia of the body changes

Question 6

Define angular impulse

Answer 6

Impulse is just a push
Angular impulse = Change in angular momentum
Txt

Question 7

Define angular momentum

Answer 7

Angular momentum quantifies the angular motion of an object.
Angular momentum (H) is the angular analog of linear momentum
H=Iω (bum)
H=angular momentum
I=moment of inertia
ω (bum)=angular velocity

Question 8

Explain the relationship between angular impulse and angular momentum

Answer 8

Angular impulse = angular momentum
Txt=Ixω (bum)