A ball at rest is dropped from a height of 12 . It losses 25 % of its kinetic energy on striking the ground and bounces back to a height ' h '. Then value of ' h ' is

Step-by-step solution

Energy of balls at rest, K₁=m g h₁ and K₂=m g h₂ percentage loss in KE = K₁-K₂ K₁ 100 array rlrl & & 25 100 & = ( 12-h^2 12 ) & 25 12 100 & =12-h₂ & h₂ & =12-3=9 ~m array