Radial acceleration in circular motion


Uniform circular motion, that is constant speed along a circular path, is an example of a body experiencing acceleration resulting in velocity of a constant magnitude but change of direction. In this case, because the direction of the object’s motion is constantly changing, being tangential to the circle, the object’s linear velocity vector also changes, but its speed does not. This acceleration is a radial acceleration since it is always directed toward the centre of the circle and is related to the angular velocity and the vector directed from the centre of the circle and equal in magnitude to the radius.

The negative shows that the acceleration vector is directed towards the centre of the circle (opposite to the radius).

Related formulas


aRadial acceleration (m/sec2)
ωAngular velocity (1/s)
rLength of the radius (m)