Uniform circular motion

Uniform circular motion describes motion in which an object moves with constant speed along a circular path. Such an object experiences a constantly changing acceleration, of constant magnitude but always changing direction, radially inwards (centripetally) at right angles to its velocity.

The magnitude of the acceleration is given by a = v² / r, where v is the speed of the object and r is the radius of its path; or equivalently, a = ωr where ω is the angular speed of the object.

The acceleration is usually considered to be be due to an inward-acting force whose magnitude (by Newton's second law of motion) is F = (mv²) / r.

The centripetal force can be provided by many different things, such as tension (as in a string), friction (as between a tire and the road), or magnetic force.

See Also

• Physics
• Circular motion
• Vector
• Centrifugal force