Optics and Momentum:
When the ball comes speeding toward a defender, it has a very high momentum. If the defender used his/her platform and passed to ball just standing there, the ball would go straight back over the net and probably even go out. The way a defender can control this is by absorbing the momentum. They do this by “breaking” their platform or cushioning the impact of the ball. A formula to show this goes like this: m1v1=m2m2. If the ball has mass m, and the person defending has mas M, and the ball is moving at velocity v, and the defender has no velocity. When the ball hits him, the defenders mass is so much greater than the ball’s his velocity will barely change. And neither will the balls. If the defender is moving backwards away from the ball, or his/her platform is at least, when the ball hits their platform, it will have a decreased velocity and is less likely to overpass. If the ball goes straight back over, it is still likely to overpass, but there is a way to solve this.
By angling you platform, you can direct the ball with more control. If the ball travels at an angle, it moves the same distance in the direction it travels, but less distance in the direction of the court. Think of the platform as a mirror, and the ball as a light ray. The angle into the platform will equal the angle out of the platform. By slightly dropping a shoulder, it rotates the platform, and changes the angles that the ball enters, relative to the platform. This is what changes the direction of the ball and allows more control.
By angling you platform, you can direct the ball with more control. If the ball travels at an angle, it moves the same distance in the direction it travels, but less distance in the direction of the court. Think of the platform as a mirror, and the ball as a light ray. The angle into the platform will equal the angle out of the platform. By slightly dropping a shoulder, it rotates the platform, and changes the angles that the ball enters, relative to the platform. This is what changes the direction of the ball and allows more control.