little bit of physics and math
back in highschool, in one of the advanced classes lead by university professors, one evening the guy brought in a bouncing ball, one of those that bounces very high because it preserves energy, they act as nearly ideal bounce balls, i.e. almost all energy of impact is preserved and minimum is lost on heat due to deformation
he drew the following on the blackboard
with following explanation:
in both pictures we discount the effect of gravity,
in the first picture we see an infinitessimally small object with ideal bounce, and no mass, we throw it towards the floor at 45 degrees, it will bounce up at 45 degrees and hit the bottom of desk, then it will bounce on again at 45 degrees
in real life however, the ball will have mass and will have non-zero diameter
as you can see in second picture, if you throw it at 45 degrees, it will also bounce at 45 degrees off the floor, but where will it go after hitting the bottom of the desk
needless to say that the answer was not as obvious and so we wrote the equations for angular momentum and energy preservation, noting that the ball touches the floor not at the center but at its very edge
the results were unexpected but simple bouncing ball and a desk proved that the results were correct.
where will the ball go?
Last edited by zmon; 05-28-2012 at 08:16 PM.
Perfect script? There is no such thing as "perfect", only "better than you expect".