A ball of mass 20 g falls from a heightof 10 m and after striking the ground.It rebounds from the ground to a height of 8 m .(a) Calculate: (i)The kinetic energy of the ball just before striking the ground ,and (ii)The loss in kinetic energy of the ball on striking the ground,and (ii)the loss in kinetic energy of the ball on striking the ground. (b)What happens to the loss in kinetic energy in part(ii) ? Take g=10 m s^(-2) Neglect air friction .

A ball of mass 20 g falls from a heightof 10 m and after striking the

1.	A ball of mass 20 g falls from a heightof 10 m and after striking the ground.It rebounds from the ground to a height of 8 m .(a) Calculate: (i)The kinetic energy of the ball just before striking the ground ,and (ii)The loss in kinetic energy of the ball on striking the ground,and (ii)the loss in kinetic energy of the ball on striking the ground. (b)What happens to the loss in kinetic energy in part(ii) ? Take g=10 m s^(-2) Neglect air friction .
Answer» Solution :(a)Given m =20 g =0.02 kg, h=10 m g=10 m `s^(-2)` h. =8 m .Air friction is negligible. (i)The kinetic energy OG ball just befire striking the ground =mitial potential energy of ball (ii)The kinetic energy of the ball just after striking the ground . Potential energy of the ball at the HIGHEST point the REBOUND =`mgh=0.02xx10xx8=1.6 J` `THEREFORE` Loss in kinetic energy on striking the ground (b)The loss in kinetic energy in part (ii)Apears in the FORM of the heat sound energies when the ball strikes the ground .