Late last week, I ran across a spectacular video of a man being completely awesome:
The video shows Christophe Hamel jumping/falling/hurtling off of walls, landing on a trampoline, and then bouncing up to land back on top of the wall — sometimes in a handstand in case there was a risk you wouldn’t be impressed enough otherwise [seen at 1:50+].
My first thought on seeing this video was “It’s gotta be really hard for his mom to watch this.”
My second thought was, “Is it really possible for a trampoline to conserve energy that well?”
Here’s the problem. In introductory physics, you learn that when something falls in a gravitational field, it turns gravitational potential energy into kinetic energy (i.e., falls down, goes faster). If that same something then bounces, it proceeds to do the reverse. To get back to exactly the same height, there cannot be any energy lost from the object — no energy lost to air resistance, or to internal motions in the object. However, in pretty much every aspect of our real world experience, we know that this perfect energy conservation doesn’t occur, leading to the following:
If you’re talking about a bouncing ball, and you ...