Q. A body of mass $2\ kg$ collides with a wall with speed $100\ m/s$ and rebounds with same speed. If the time of contact was 1/50 second, the force exerted on the wall is
A) $8\ N$
B) $2 \times 10^{4}\ N$
C) $4\ N$
D) $10^{4}\ N$
Explanation
(b) $F = \frac{dp}{dt} = m\frac{dv}{dt} = \frac{m \times 2v}{1/50} = \frac{2 \times 2 \times 100}{1/50} = 2 \times 10^{4}N$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.