Q. The average resisting force that must act on a $5\ kg$ mass to reduce its speed from $65\ cm/s$ to $15\ cm/s$ in $0.2s$ is
A) $12.5\ N$
B) $25\ N$
C) $50\ N$
D) $100\ N$
Explanation
(a) $F = m\left( \frac{v - u}{t} \right) = \frac{5(65 - 15) \times 10^{- 2}}{0.2} = 12.5\ N$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.