Momentum - Inelastic Collisions - Modified Newton's Cradle

  

This is a great demonstration for demonstrating the loss of kinetic energy in an inelastic collision. Notice the hook below one of the tennis balls, allowing for mass to be added to this ball. The tennis balls are each a little over 50 g (about 58 g), so adding a 50 g hanger effectively doubles the mass.

The picture below shows the scale included to help show the change in height. Each line represents 1 inch. The loss in kinetic energy can be best seen by the change in potential energy at the top of the swing, hence the height markings.