Question

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

Answer 1

Answer:

t=3s

Explanation:

Let the stone taken n second to reach the ground

Given, u=0,a=+g

The distance covered in nth second

9

5

×distance covered in n seconds

2

g

(2n−1)=

9

5

×

2

g

n

2

⇒18n−9=5n

2

⇒5n

2

−18n+9=0

so, n=3s or 0.6s

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