AP Physics C Rotation Questions

Front

What is rotational inertia (moment of inertia)?

Back

Rotational inertia, or moment of inertia (I), is a measure of an object's resistance to changes in its rotation. It depends on the mass distribution relative to the axis of rotation.

Front

What happens to angular speed when moment of inertia increases?

Back

When the moment of inertia increases, the angular speed decreases, assuming no external torque is applied. This is due to the conservation of angular momentum.

Front

Define angular momentum.

Back

Angular momentum (L) is the product of an object's moment of inertia and its angular velocity, given by the formula L = Iω.

Front

What is the relationship between linear speed and angular speed?

Back

Linear speed (v) is related to angular speed (ω) by the equation v = rω, where r is the radius from the axis of rotation.

Front

What is the effect of extending arms while spinning on a stool?

Back

Extending arms increases the moment of inertia, which decreases angular speed due to conservation of angular momentum.

Front

How does mass distribution affect rotational motion?

Back

The distribution of mass affects the moment of inertia; more mass further from the axis increases the moment of inertia, making it harder to change rotational speed.

Front

What is the formula for calculating the moment of inertia of a solid disk?

Back

The moment of inertia (I) of a solid disk about its center is given by the formula I = \frac{1}{2}MR^2, where M is the mass and R is the radius.

Front

What is the principle of conservation of angular momentum?

Back

The principle states that if no external torque acts on a system, the total angular momentum of the system remains constant.

Front

How do you calculate the angular displacement of a rotating object?

Back

Angular displacement (θ) can be calculated using the formula θ = ωt + \frac{1}{2}αt^2, where ω is the initial angular velocity, α is the angular acceleration, and t is time.

Front

What is the relationship between torque and angular acceleration?

Back

Torque (τ) is related to angular acceleration (α) by the equation τ = Iα, where I is the moment of inertia.