Rotational Motion

Basics and Definitions

100

This type of motion describes an object moving in a circular path around a fixed axis.

Rotational Motion

200

The fixed line or point around which an object rotates is called this.

Axis

300

Our presentation compares these two types of motion to highlight similarities in kinematics and dynamics.

Rotational and Linear motion.

400

This system of angle measurement (not degrees) is used for rotational kinematics.

Radians

500

This term refers to an object that does not change shape or size as it undergoes rotational motion.

Rigid Body

Angular Kinematics

100

The symbol θ represents this rotational quantity.

Angular Displacement

200

This symbol (ω) represents the rate of change of angular displacement.

Angular Velocity

300

This rotational quantity, symbolized by α, is directly analogous to linear acceleration.

Angular Acceleration

400

If two particles share the same angular velocity but one has twice the radius, this happens to its tangential speed.

It doubles.

500

A diagram shows one particle moving twice as fast in linear speed while having the same angular velocity as another; this is because this quantity differs between them.

Radius

Energy and work

100

What is the equation for Rotational Kinetic Energy?

KE_rot=1/2Iω²

200

This type of energy is stored in a spinning object

rotational kinetic energy

300

This type of energy is the "straight-line" version of rotational kinetic energy.

translational kinetic energy

400

When an object rolls down a hill, potential energy turns into rotational energy and this other type.

translational kinetic energy

500

Work is the change of this quantity.

Energy

Inertia

100

This quantity measures how hard it is to start or stop rotation.

Moment of Inertia

200

Moment of inertia depends on mass and its distance from this.

axis of rotation

300

What is the symbol for Moment of Inertia?

I

400

When a skater pulls their arms in and speeds up, what happens to the moment of Inertia?

Decreases

500

If the mass is farther from the axis, moment of inertia does this.

It increases.

Torque and Dynamics

100

Torque is the rotational version of this.

Force

200

What is the equation for Torque?

τ=rFsin(θ)

300

When pushing a door closer to the hinges, do you produce more or less torque?

less torque

400

The distance from the axis to where force is applied is called this.

lever arm

500

Applying equal forces at different distances from the pivot can produce different amounts of this rotational effect.

Torque