Hi! I've attempted to draw the position, velocity and acceleration graphs for a bouncing ball. This is the link for it: http://i196.photobucket.com/albums/aa59/aliatehreem/bouncing_ball.jpg What i'm wondering is, the instant in which the ball is in contact with the ground, is the acceleration zero, which is why there are circles? Just wanted to confirm that! [as there is no acceleration due to gravity?] Thanks in advance!