Question

A boy standing near the edge of a cliff 125 m above a river throw a stone downward with a speed of 10 ms. find
A. with what speed will the stone hit water and
B. how long will it take to descend

Answer 1

hope it may help yu
I know it not clear

Answer 2

Hey.

Here is the answer.

s = 125 m

u = 10 m/s

a = g = 10 m/s^2

A.

As,


${v}^{2} - {u}^{2} = 2as$
so,


${v}^{2} - {10}^{2} = 2 \times 10 \times 125$
or,

${v}^{2} = 2500 + 100 = 2600$

So, v = √2600 = 50.99 m/s

So, it will hit with a velocity of 50.99 m/s

B. as V = u + a t

so , 50.99 = 10 + 10 t

or, 40.99 / 10 = t

so, time taken to decent = 4.099 second

Thanks .