Question

A particle of mass $1kg$ is projected with a velocity of $20m/s$ at an angle of ${30}^{\circ }$ with the horizontal. Find the change in the momentum $(kg-m/s)$ of the particle between the points of projection and the highest point. Take $g=10m/s^2$

• A. $20$
• B. $10$
• C. $30$
• D. $40$

Answer 1

The correct option is B $10$

Since the velocity is constant in the horizontal direction, momentum will change only in vertical direction. At the highest point, velocity in the vertical direction is zero.
Hence, $\Delta p=mu\sin \theta =1\times 20\times \frac{1}{2}=10kg-m/s$