Question

A ball of mass $600gm$ strikes a wall with a velocity of $5m{s}^{-1}$ at an angle ${30}^o$ with the wall and rebounds with the same speed at the same angle with the wall. The change in momentum with a ball is, (in $kg{s}^{-1}$):

• A. $15$
• B. $10$
• C. $5$
• D. $3$

Answer 1

The correct option is D $3$

change in momentum is perpendicular to the wall

change in momentum=$mvsin\theta -(-mvsin\theta )=2mvsin\theta =2\times 0.6\times 5\times \frac{1}{2}=3$