Question

A body of mass $0.05kg$ travelling with a velocity of $5m/s$ makes an angle of ${30}^{\circ }$ with the wall as shown. The body rebounds with the same speed making an angle of ${30}^{\circ }$ with the wall. Find the change in momentum of the body in $Ns$.

• A. 0.25
• B. 0.5
• C. 0.75
• D. 1

Answer 1

The correct option is A 0.25

Considering left to be positive direction,
$u=-5\sin {30}^{\circ }$
$v=5\sin {30}^{\circ }$
$p=m(v-u)$
$=5\times {10}^{-2}(\frac{5}{2}+\frac{5}{2})$
$=0.25Ns$