Question

A boy standing at the top of a tower of 20m height drops a stone. Assuming g = 10 ms−2 , the velocity with which it hits the ground is


(a) 10 m/s

(b) 20 m/s

(c) 40 m/s

(d) 5 m/s

Answer 1

Answer:

20

Explanation:

$v^{2}$   = $u^{2}$ + 2gh

here u=0

so,

v = $\sqrt{2gh}$  

v = $\sqrt{2*10*20}$

v = 20