A Ball That Bounces Higher Than Its Dropping Point

James Orgill of The Action Lab explores the physical science behind the coefficient of restitution, a formula that explains why a ball can’t bounce higher than the point from which was dropped, neither exerting nor absorbing energy.

Normally when you drop a ball it can’t bounce higher than the height it started from due to the conservation of energy but not this one. …in a best case scenario the highest that the ball can bounce to is exactly the point that it was dropped from …the height that a ball gets to after it’s dropped depends on its coefficient of restitution. The higher this coefficient the closer it gets to the original height.

He also explained that with every rule, there is an exception. That exception, in this particular situation, is a half-sphere inside the ball that gains and releases energy to allow the ball to bounce higher than its dropping point.

With this hollowed out half-sphere here we can inverse it. This provides a bunch of energy stored elastically in the bonds of the rubber and then when I drop it, the energy is released and the shell reverses its shape and the middle hits the ground at high speed this sends it flying in the air way higher than where you dropped it from. 

Lori Dorn
Lori Dorn

Lori is a Laughing Squid Contributing Editor based in New York City who has been writing blog posts for over a decade. She also enjoys making jewelry, playing guitar, taking photos and mixing craft cocktails. Lori can be found posting on Threads and sharing photos on Instagram.