Question

a stone is dropped from height of 20 m. a) how long will take to reach the ground? b)what will be its speed when it hits the ground? The value of g is 10 metre per second square

Answer 1

v²-u²=2as

V= final velocity(?)

U= Initial velocity (zero)

a = acceleration (10m/s given)

s = Distance to be travelled( 20mts.)

U(initial vel.) Is zero, because the stone is thrown without any I initial push, it's just thrown from the rest.

So:-

v²-(0)²=2(10).(20)

>v²=20.20 =400

>v= 20

V=U+AT
>20=0+10T
>T=2sec

I hope this will help you