Circular Motion

Centripetal Force

A net force that results in an object following a curved path. The direction of the net force is toward the center of rotation/revolution.

Tangential Velocity

A object moving in a curved path will have a velocity that is tangent or parallel to the curve at that particular part of the path.

Comparative problem

A problem that changes one variable and ask for the effect on another variable. For example, centripetal acceleration is directly proportional to the square of the object's tangential velocity and inversely proportional to the radius of the curvature (circle). An exception exist when comparing two objects of different radii but equal periods of rotation. For example, a bug rotating twice the radius from the center of rotating platform will have twice the tangential speed when compared to a closer bug. This means the bug should have 4 times the acceleration, but since it is 2 times farther the actual increase is only 2 times the acceleration.

Uniform Circular Motion

A state of motion defined by constant tangential speed and a net force that constantly points toward the center of rotation/revolution.

Centrifugal Force

An apparent outward force that pushes or pulls an object away from the center of rotation. Centrifugal force is the result of inertia of the object and the rotation of the frame of reference.

Centripetal Acceleration

Centripetal acceleration is directly proportional to the square of the object's tangential velocity and inversely proportional to the radius of the curvature (circle).

"Toward the center"

Centripetal...Centripetal Force...Centripetal Acceleration

Tangential Speed

The magnitude of the tangential velocity of an object moving in a curved path.

Period, T

The time for the completion of one cycle of a periodic event. For example, one year is the period of time it takes the Earth to revolve around the Sun once.