2. Do you know what energy is ? Energy is the ability to do work or cause change. Power is the rate at which energy is transferred. In every movement energy is used. Well, today I will show you how many Energy transfers/transformation there are in Tennis and you will be surprised how many there are.

4.  I have Gravitational Potential Energy.  Because I am holding my ball in my hand and it is not moving  and because it is also over the surface

5.  Chemical Energy is transformed to Kinetic Energy.  This makes my hands swing back and then forward to hit the ball.

6.  When the kinetic energy reaches the ball it is transferred from the tennis racket to the ball.  Please do not forget: If I would shoot the ball with a wooden board it would never get as high as with the tennis racket because of the string. So elastic potential energy from the racket helps it get higher. Kinetic Energy of my racket hits the ball, Energy is lost due to Sound Energy.

7.  THE WHOLE FLIGHT OF THE BALL IS KINETIC ENERGY  If I hit the ball very strong it will fly farther than if I hit it softly.  When the ball reaches it highest spot, it is still KE but it is also Gravitational Potential Energy because now it just has to fall down.

8.  When the ball hits the ground a bit of Kinetic Energy is transformed into Sound Energy.  The ball didn’t stop, it keeps bouncing and rolling.  When I drop most objects they make a sound.  Can anyone think of a object that if you drop it from for example 1 Meter it will not make a sound?

9.  The tennis ball has not stopped yet. It will start bouncing  For every bounce the KE is transformed into GPE when the ball is at its highest spot of the bounce  Then it is transferred back into KE  Each time the tennis ball bounces up it will bounce down until it will end still.