Question

A stone is dropped on the moon from a height of $30m$. The acceleration due to gravity on the moon is $\frac{g}{6}$. Determine the approximate time taken by the stone to fall on the surface of the moon.
(Take $g=10m/s^2$ )

• A. $2sec$
• B. $3sec$
• C. $5sec$
• D. $6sec$

Answer 1

The correct option is D $6sec$

Given :
$u=0m/s$
$s=30m$
$a=\frac{g}{6}=\frac{10}{6}m/s^2$

Using second equation of motion,
$s=ut+\frac{1}{2}a{t}^2$
$30=0+(\frac{1}{2}\times \frac{10}{6}\times t^2)$
$t^2=36$
$t=6sec$