'''
Created on 8 juil. 2012

@author: Laurent
'''
from vpython import box, sphere, vector, color, rate

floor = box(pos=vector(0, 0, 0), length=4, height=0.5, width=4, color=color.blue)
ball = sphere(pos=vector(0, 4, 0), radius=1, color=color.red)
ball.velocity = vector(0, -1, 0)
dt = 0.01

while 1:
    rate(100)
    ball.pos = ball.pos + ball.velocity * dt
    if ball.pos.y < ball.radius:
        ball.velocity.y = abs(ball.velocity.y)
    else:
        ball.velocity.y = ball.velocity.y - 9.8 * dt
