Question

From the top of a 490m high cliff, a boy throws a stone horizontally with an initial speed of 15m/s. What is the time taken by the stone to reach the ground?

Answer 1

s=ut +1/2gt^2

root (2s/g)

root( 2*490/9.8)=t

root(980/9.8)=t

root(100)=t

10s=t

time taken is 10 sec

Answer 2

Answer:

Explanation:

√2H/g

2×490/9.8

√100

10