Kinematics of rotational motion

Definition

Kinematics of rotational motion describes the motion of objects rotating around a fixed axis. It involves quantities like angular displacement, angular velocity, and angular acceleration.

5 Must Know Facts For Your Next Test

1. Angular displacement is measured in radians and represents the angle through which an object has rotated.
2. Angular velocity is the rate at which an object rotates, typically measured in radians per second ($\text{rad/s}$).
3. Angular acceleration is the rate of change of angular velocity, usually measured in radians per second squared ($\text{rad/s}^2$).
4. Equations for rotational motion with constant angular acceleration are analogous to those for linear motion with constant acceleration.
5. The moment of inertia plays a similar role in rotational motion as mass does in linear motion, determining how much torque is needed for a given angular acceleration.

Review Questions

• How do you calculate angular displacement if you know the initial and final angles?
• What is the relationship between tangential speed and angular speed?
• How does moment of inertia affect an object's rotational motion?

Related terms

Moment of Inertia: A quantity expressing an object's tendency to resist angular acceleration.

Torque: A measure of how much a force acting on an object causes that object to rotate.

Centripetal Acceleration: $\text{Acceleration}$ directed towards the center of a circular path, necessary for maintaining circular motion.