Rotational Kinematics and Angular Motion Concepts

Angular Displacement

The angle swept out by a line passing through any point on a rigid body and intersecting the axis of rotation perpendicularly.

SI Unit of Angular Displacement

radian (rad)

Average Angular Velocity

The rate at which the angular displacement is changing.

SI Unit of Angular Velocity

radian per second (rad/s)

Average Angular Acceleration

The rate of change of angular velocity.

SI Unit of Angular Acceleration

radian per second squared (rad/s²)

Angular Speed

The rate of rotation of an object, measured in radians per second.

Angular Acceleration

The rate of change of angular velocity over time.

Example of Angular Acceleration Calculation

A jet's fan blades rotate from -110 rad/s to -330 rad/s in 14 s.

Example of Angular Displacement Calculation

A blender's blades rotate through an angular displacement of +44.0 rad.

Final Angular Velocity

The angular velocity of the blades after accelerating with a constant angular acceleration of +1740 rad/s².

Tangential Speed

The linear speed of a point on the outer edge of a rotating object.

Tangential Acceleration

The acceleration of a point on the outer edge of a rotating object.

Centripetal Acceleration

The acceleration directed towards the center of a circular path.

Rolling Motion

The motion of an object where linear velocity and acceleration are accompanied by angular acceleration and velocity.

Right-Hand Rule

A method to determine the direction of angular velocity by grasping the axis of rotation with the right hand.

Example of Car Acceleration

A car accelerates from rest for 20.0 s with a constant linear acceleration of 0.800 m/s².

Radius of Tires

The distance from the center of the tire to its outer edge, given as 0.330 m.

Angular Separation of Satellites

The angle between two synchronous satellites, given as 2.00 degrees.

Arc Length

The distance that separates two points along a circular path, calculated based on angular separation.

Gymnast's Average Angular Velocity

The average angular velocity of a gymnast swinging through two revolutions in 1.90 s.