Answer:
the ball rebounds 8 times before losing 90% of its energy
Explanation:
given information:
height, h₁ = 1.6 m
rebound height, h₂ = 1.2 m
energy loss = 90% = 0.9
first we can calculate the loss energy after the rebound
energy loss = 1 - [(height of rebound/height of the ball)^n
where
n = number of the bounce
energy loss = 1 - (h₂/h₁)^n
0.9 = 1 - (1.2/1.6)^n
(0.75)^n = 1 - 0.9
n log 0.75 = log 0.1
n = log 0.1/log 0.75
= 8 bounces
