Circular motion can be a tough topic to teach because some aspects of it are counterintuitive. This is a really simple and elegant way to get across some of the key ideas needed to grasp the physics of what’s going on when an object moves in uniform circular motion.

The film was shot and edited by Ed Prosser. The Ogden Trust kindly helped with equipment costs and David Sang advised on the script.

One you’ve demonstrated that the velocity of an object in uniform circular motion is at a tangent to the circle, you can show that the acceleration is always directed towards the centre of the circle using this:

For more physics demonstration films, click here.