Question

A ball is thrown vertically upwards with a velocity of 20ms-1 from the top of a building. The height of the point from where the ball is thrown is 25.0m from the ground.

How heigh will the ball rise?

How long will it be before the ball hits the ground?​

Answer 1

Answer:

it will rise to the height 20m from top of building and 55m from ground

and it will take 5s to reach the ground

Explanation:

at topmost point it's velocity will be zero

so

by applying

third equation of motion

v^2=u^2+2as

a=-g because velocity is upward

so

v=0

s=u^2/2g

s=(20×20)/(2×10) g=10m/s^2

so

s=20m