Question

A ball is thrown vertically upwards with initial velocity of $49m{s}^{-1}$. Calculate the maximum height attained.
(Take $g=9.8m{s}^{-2})$

Answer 1

Given,
Initial velocity, $u=49m{s}^{-1}$ and,
$a=-g=-9.8m{s}^{-2}$
Let $H$ be the maximum height attained.
At the highest point, velocity $v=0$
Using the third equation of motion for ball in free fall,
$v^2-u^2=2aS$
$0^2-(49{)}^2=2(-9.8)\times H$
$H=122.5m$
Hence, the maximum height attained by the ball is equal to $122.5m$.