Question

A ball is thrown 125 meters upward and then falls the same distance back on earth. Neglecting air resistance, its total time in the air is

Answer 1

Solution.

$h=125m;$

$h=\dfrac{gt^2}{2};$

$t^2=\dfrac{2h}{g};$

$t=\sqrt{\dfrac{2h}{g}};$

$t=\sqrt{\dfrac{2\sdot125}{10}}=5s;$

The fall time is equal to the rise time to the same height.

Answer: 10s.