# Centripetal Force & Centrifugal Force

Centripetal force is a force on an object directed to the center of a circular path that keeps the object on the path. Its value is based on three factors:

• The velocity of the object as it follows the circular path.

• The object's distance from the center of the path.

• The mass of the object.

Centrifugal force, on the other hand, is not a force, but a tendency for an object to leave the circular path and fly off in a straight line. Sometimes people mistakenly say 'centrifugal force' when they mean 'centripetal force.' The velocity of the object is constant and perpendicular to a line running from the object to the center of the circle; it is called tangential velocity.

An object on a circular path

In this diagram, centripetal force f is shown as a red arrow. It is constant in magnitude but keeps changing direction so that it is always pointing to the center. Also shown on the diagram is the tangential velocity, v. Finally, the constant distance of the object from the center of the circle is represented by the variable r, or radius