I've done an experiment where I dropped 3 balls from a meter high and I want to record the energy loss they get once they bounce. I have height measurements for the first fall and the bounce. How would I calculate energy loss from this?
If initial height is $h_1$ ,then the Kinetic energy $KE_1$ of the ball just before the impact would be $mgh_1$ from conservation of energy.During the impact some non conservative forces act on the object and takes some of its kinetic energy (as heat/sound losses).Just after the impact say the kinetic energy is $KE_2$, if it reaches a height $h_2$, then $KE_2$=$mgh_2$.
So magnitude of loss of energy = |Work done by non conservative force|= |Initial Kinetic energy - Final Kinetic Energy|=$mg(h_1-h_2)$ (Work energy theorem)