Question

A stone dropped from the top of a tower is found to
travel 5/9 of the height of the tower during the last
second of its fall. The time of fall is

Answer 1

Explanation:

Let the stone taken n second to reach the ground

Given, u=0,a=+g

The distance covered in nth second 95×distance covered in n seconds

2g(2n−1)=95×2gn2

⇒18n−9=5n2⇒5n2−18n+9=0

so, n=3s or 0.6s

But 0.6s time is practically not possible, hence t=3s