Set of the bearing track on a level, stable surface. The spring should be attched to one end of the track and attached at the other end to a bearing cart.The bearing cart should have a flag inserted into the top to signal the photogate. A photogate should be put up just past where the spring's point of zero displacement is.
The cart is struck by a hammer with an arbitrary force. Upon impact, the energy from the hammer will be completely transfered to the other cart. That cart, as it moves will displace the spring transferring its kinetic energy into potential energy of the spring
This demonstration happens in five stages: The first stage is at the time of impact just before the spring begins to move. (the closer the photogate is placed to the zero point, the better estimation of the energy at this state will be.) The second stage is when the second bcart is displacing the spring. the third stage is when the spring and cart are both at rest (when all of the energy is in the form of potential energy). The fourth stage is when the spring is moving the block away. And the fifth state is when the cart moves past the photogate to the zero point