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ACTIVITY 3
Take a ping-pong ball. Release it from a height on
a hard, smooth floor. You will observe that the ball
after striking the floor bounces several times. Try to
answer the following questions :
(a) What is the potential energy and kinetic energy
when you release the ball ?
(b) Why does the ball bounce back after striking
the floor?
(c) From where does the ball get the kinetic energy
for motion after striking the floor ?
(d) What happens to the energy of the ball when
the ball stops bouncing ?
Answers
Answer:
a) Potential energy is the energy possesd by an object in the state of rest
Kinetic energy is the energy possesd by the object in the state of motion
b) It bounces back because of the when the ball hits the ground, it is pressed with a force of gravity and other forces that was exerted on it. Due to these forces it's shape is deformed and to retain back its shape, its elastic nature exerts the same amount of force that deformed it. So the ball bounces until it gains back its shape
c)As the ball falls towards the ground, its gravitational potential energy is transformed into kinetic energy
d)The force of gravity pulls it down, and as the ball falls, its potential energy is converted to kinetic energy. This is because the ball had an inelastic collision with the ground. After a few bounces, it stops bouncing completely. The energy has left the ball!