Hi

I am struggling with this question. It goes like this:

A rubber ball is dropped on to flat ground from a height of 2m.

(a) Calculate how long it takes for the ball to first hit the ground.

(b)The ball loses 10% of its kinetic energy at each bounce. Calculate the time taken for the ball to come to rest.

I am able to solve the first part using equation of motion.

S=UT +0.5aT^2

I am not sure of the second part.