Q. The kinetic energy acquired by a body of mass $m$ in travelling some distance $s$, starting from rest under the action of a constant force, is directly proportional to
A) $m{^\circ}$
B) $m$
C) $m^{2}$
D) $\sqrt{m}$
Explanation
(a) K.E. acquired by the body = work done on the body
$K.E. = \frac{1}{2}mv^{2} = Fs$ $i.e.$ it does not depend upon the mass of the body although velocity depends upon the mass
$v^{2} \propto \frac{1}{m}$ [If $F$ and $s$ are constant]
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.