0
$\begingroup$

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?

$\endgroup$
  • $\begingroup$ Would the change in potential energy suffice? That would mean energy lost is given by $mg\Delta h$ where $\Delta h$ is the change in height $\endgroup$ – user3518839 Mar 29 '19 at 4:26
  • $\begingroup$ Would that be mg(h1 - h2)? The main problem I'm having here is that I can't find the source of that equation, so if that is it, then that's this question answered I guess. $\endgroup$ – liaquore Mar 29 '19 at 4:30
  • $\begingroup$ Yes. That’s right. If there was no energy loss, it’d have gone back up to the same height. But it loses some energy as heat and sound while bouncing. As for source here hyperphysics.phy-astr.gsu.edu/hbase/gpot.html $\endgroup$ – user3518839 Mar 29 '19 at 4:32
0
$\begingroup$

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)

$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.