Question

A rubber ball is dropped from an initial height of 40 feet. The ball consistently rebounds to 80% of its previous height

Answer 1

The ball travels (exactly) 75 feet.

Explanation:

Assuming the balls comes to rest:

S = a1 / (1 - r)

Now a1 is the first bounce, 20 ft (10 feet up, 10 feet down.

r is 2/3

S = 20 (1 / (1 - 2/3)

S = 20 / (1/3)

S = 60

Yet that is only the bounce. The drop of 15 feet must be added.