Question

The kinetic energy acquired by a mass m in travelling distance d, starting from rest, under the action of a constant force is directly proportional to

• A. m
• B. m$^0$
• C. $\sqrt m$
• D. 1$\sqrt m$

Answer 1

The Correct Option is B

$v^2=u^2+2as$ or $v^2-u^2=2as$
or $ \, \, v^2-(0)^2=2 \times \frac{F}{m} \times s $ or $v^2 =\frac{2Fs}{m}$ and
K.E =$\frac{1}{2}mv^2=\frac{1}{2}m \times \frac{2Fs}{m}=Fs.$
Thus K.E. is independent of m or directly proportional to m$^0$.