This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Initial height = 128m

coefficient of restitution(n) =  \frac{V_{after impact} }{V_{before impact}}   (by definition)

Also coefficient of restitution(n) = √( \frac{h_{0} }{h_{1}} )

where h₀ = initial height from which it is dropped
           h₁ = height upto which it goes after impact

After first impact, n = √( \frac{h_{0} }{h_{1}} )

                             ⇒h₁ = h₀.n²

After second impact, n = √( \frac{h_{1} }{h_{2}} )

                             ⇒h₂ = h₁.n² = h₀.n²*²

After third impact, n = √( \frac{h_{2} }{h_{3}} )

                             ⇒h₃ = h₂.n² = h₀.n²*³

After mth impact, n = √( \frac{h_{m-1} }{h_{m}} )

                             ⇒hm = h(m-₁).n² = h₀.(n^(2m))

Thus, for third impact, m=3
h₃ = h₀.n²*³ = 128.(1/2)⁶ = 128/64 = 2m

1 5 1
clearly understood
second formula for restitution is important, try to derive it. I have directly given it.
Then my efforts have some value. I am glad.
it was explained in my book too but i was not able to understand it so thanks
welcome buddy!!