Question

plz answer it's urgent

Answer 1

The ball bounces 80% of it's original height with each consecutive bounce, so

the ball loses 20% of it's original height or 1/5 f its original height

Answer 2

As the ball bounces about 80percent out of 100,20 percent of it lost by the ball,i.e. 1/5 of the mechanical energy is lost by it