Uniform circular motion

• A motion along a circular path is called as a circular motion. When a body (or object) moves along a circular path, then its direction of motion (or direction of speed) keeps changing continuously. As the velocity changes (due to continuous change in direction) So, the motion along a circular path is said to be accelerated.
• Where a body moves in a circular path with uniform speed (constant speed), its motion is called uniform circular motion.
• A circular path can be considered to be made up of an indefinite number of tiny sides, and a body moving along such a circular path changes its direction of motion continuously.

Examples of Circular Motion:

1. Artificial satellites move under uniform circular motion around the earth. Their motion is accelerated. The velocity (speed) is constant but the direction keeps on changing.

2. The moon moves in a uniform circular motion around the earth. It is the force of gravity (centripetal force) of the earth which keeps the motion in the circular orbit.

3. The tip of a second’s hand of a watch exhibits uniform circular motion on the circular dial of the watch.

4. An athlete moving on a circular track with a constant speed exhibits uniform circular motion.

A toy train moving on a circular track

A merry go Round

Some other Examples of Non-uniform Circular Motion:

1. A car negotiating a curve with uniform speed

2. An aircraft moving in a loop.