Q. The kinetic energy $K$ of a particle moving along a circle or radius $R$ depends on the distance covered $s$ as $K = a\ s^{2}$. The force acting on the particle is
A) 2 $a\ s\ R$
B) 2 $a\ s\left\lbrack 1 + s^{2}/R^{2} \right\rbrack^{1/2}\ \ $
C) 2 $a\ s$
D) 2 $as^{2}/R$
Explanation
(d) Kinetic energy $= \frac{1}{2}mv^{2} = K = as^{2}$
or $mv^{2} = 2as^{2}$
Centripetal force = $\frac{mv^{2}}{R} = \frac{2as^{2}}{R}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.