Aim:
The aim of this experiment is to investigate the efficiency of a bouncing ball, and the factors which affect its efficiency.
Prediction I predict that the higher I drop the ball from the higher it will rebound up, because it will have more gravitational potential energy the higher dropped from. As it is dropped the ball will have kinetic energy, and then when it hits the ground changes to heat and sound energy, and kinetic as it rebounds back up. The higher up the ball is dropped from the more gravitational potential, more kinetic energy on the way down and therefore more sound heat and kinetic energy when hitting the ground. The ball will bounce higher the higher dropped from as the energy has to go somewhere! The ball 's efficiency (what fraction of the energy the ball has left after being dropped), will when dropped from a small height i.e. 25cm, be a high percentage, because air resistance won 't affect the ball. As the height dropped from increases the ball will bounce higher but the amount it increases by will get less. (See graph) This is because as the ball is dropped from a higher height the amount of kinetic energy on the way down is greater, this could make the ball reach terminal velocity, but even if it does not air resistance will affect it more. The ball will reach a certain height where it reaches terminal velocity on the way down and will rebound up as high as it if it was dropped from a higher height.
Theory:
The ball has gravitational potential energy at point A just before it is released.
As the ball falls from point A to B it has kinetic energy.
At B just before the ball hits the surface it has gravitational potential and kinetic energy.
When the ball hits the surface and deforms it has elastic energy.
At point C when the ball is rebounding and travelling upwards it has kinetic energy.
At point D when the ball has reached its maximum rebound and is momentarily stationary it has