Bouncing Balls

Some balls bounce better than others.

A particular ball can be characterized by its

The ratio of its rebound speed Vf to its collision speed Vi Scientists have found that, for most balls, this speed ratio The amount of kinetic energy transformed at impact is called This java applet shows you the effects due to

1. You can enter different value of coefficient of restitution as (Vo/Vi).

2. You can change the initial velocity Vx of the ball. 3. You can change the initial height  (drag it up and down with mouse left click)

4. Press Start button to start/restart animation.

4. Press Reset button to reset parameters to its default value. 5. Press the mouse button to pause the animation 6. The mouse coordinate (X,Y) will be shown when its inside the window.

You should be able to get some graph like this (click me).

Your suggestions are highly appreciated!

E-mail : Please click

Author¡GFu-Kwun Hwang, Dept. of physics, National Taiwan Normal University
Last modified : 

Subject: bouncing ball
Date:  Fri, 21 Apr 2000 05:01:29 -0400
From: David and Carol <>

the above site has been helpful in a differential equations project I am
currently undertaking. One thing that would make your applet invaluable to
me is if heights were marked on the picture of the bouncing ball. I am
measuring the height of a ball and am trying to find it's coefficient of
restitution. Is there anyway of setting initial heights on your applet and
finding the maximums of each consecutive bounce?

thank you,
The code was modified according to David's suggestion Apr. 21, 2000