Question

An object takes $5s$ to reach the ground from a height of $5m$ on a planet. What is the value of $g$ on the planet?

Answer 1

Given,

Initial velocity = $u=0m/s$

Displacement = $s=5m$

Time taken = $t=5s$

Using the first equation of motion $s=ut+\frac{1}{2}g{t}^2$ we get

$5=0\times 5+\frac{1}{2}\times g\times (5{)}^2$

$\frac{2\times 5}{(5{)}^2}=g$

$\Rightarrow g=\frac{2\times 5}{5\times 5}$

$=0.4m/se{c}^2$