Question

A body is released from a great height falls freely towards the earth. Another body is released from the same height exactly a second latter. Then the separation between two bodies, $2s$ after the release of the second body is, nearly

• A. 15 m
• B. 20 m
• C. 25 m
• D. 30 m

Answer 1

Answer: (C)

$s=ut+\frac{1}{2}a{t}^2$
For 1st body $u=0$ and a $=g$ (freely falling body)
Distance covered in $2s$
$s_1=0+\frac{1}{2}g(2{)}^2$
For 2 nd body Distance covered in $2s$
$s_2=0+\frac{1}{2}g(3{)}^2$
hence $s_2-s_1=\frac{1}{2}g\left[(3{)}^2-(2{)}^2\right]$
$=\frac{1}{2}g[9-4]$
$=25m$