course phy 201
I wanted to finish calculating the change in potential energy for the rubber band chain that I used in this experiment to find out if the change in potential energy is close to the change in kinetic energy and I figured out that I would need to know the length of each rubber band when it is stretched out for each weight increment. If I knew how long each band in the chain was when it was stretched out then I could accurately figure out the delta y for each weight increment since the bands higher up in the chain do not travel as far as the bands lower in the chain. We took down the rubber band chain today for the in class experiment. Is there another way that I can calculate the change in potential energy from the total stretched length of the rubber band chain and the distance of the bounce back up after the weights are dropped off?
You could assume that the 'stretch' of the system is more or less equally distributed among the rubber bands. However you wouldn't need to calculate the elastic PE of each band. If you calculate just the increase in gravitational PE for each, you can compare the total increase in gravitational PE with the initial elastic PE of the system.
You know the PE of the stretched chain, and you know how far the chain was stretched. If you assume that the rubber bands were equally spaced at the 'stretched' position you can figure out with reasonable accuracy where each band and each clip was at the instant of release; if you then have a reasonable picture of the configuration of the chain at its 'highest' point, you should be able to estimate how much higher each component of the chain is than at the stretched position, and you can use this as a basic for calculating its increase in gravitational PE.