If you hold a rock 10 ft high instead of 3 ft high before you
drop it on your foot, it'll hurt more, because of the greater
amount of potential energy that changed to kinetic energy
on the way down before it landed with a 'crunch'.
Also, you have to use more energy to lift it all the way up
to 10 ft. That increased lifting energy that you use gets
stored in the ball, as additional potential energy.
