AP Physics Rotation Quick Review

Front

What is torque?

Back

Torque is a measure of the rotational force applied to an object, calculated as the product of the force and the distance from the axis of rotation (lever arm).

Front

What is the condition for an object to be in rotational equilibrium?

Back

An object is in rotational equilibrium when the sum of all torques acting on it is zero, meaning it is either at rest or rotating at a constant angular velocity.

Front

How is angular velocity defined?

Back

Angular velocity is the rate of change of angular displacement with respect to time, typically measured in radians per second (rad/s).

Front

What is the relationship between linear velocity and angular velocity?

Back

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

Front

What happens to mechanical energy during an inelastic collision?

Back

In an inelastic collision, mechanical energy is not conserved; some of it is transformed into other forms of energy, such as heat or sound.

Front

What is the formula for calculating torque?

Back

Torque (τ) is calculated using the formula τ = rF sin(θ), where r is the lever arm, F is the force applied, and θ is the angle between the force and the lever arm.

Front

What is the significance of the lever arm in torque calculation?

Back

The lever arm is the perpendicular distance from the axis of rotation to the line of action of the force; a longer lever arm increases the torque for the same amount of force.

Front

What is angular momentum?

Back

Angular momentum (L) is the rotational equivalent of linear momentum, defined as L = Iω, where I is the moment of inertia and ω is the angular velocity.

Front

How does the moment of inertia affect rotational motion?

Back

The moment of inertia is a measure of an object's resistance to changes in its rotational motion; a larger moment of inertia means more torque is required to achieve the same angular acceleration.

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 that system remains constant.