Question

A body of mass $60kg$ has the momentum $3000kgm{s}^{-1}$. Find the kinetic energy.

• A. $25kJ$
• B. $50kJ$
• C. $75kJ$
• D. None of these

Answer 1

Answer: (C)

$75kJ$

Given, $m=60kg,p=3000kgm{s}^{-1}$

$\therefore$ Kinetic Energy$=\frac{1}{2}m{v}^2$

$=\frac{1}{2}\times \frac{{\left(mv\right)}^2}{m}=\frac{1}{2}\times \frac{p^2}{m}$

$=\frac{1}{2}\times \frac{{\left(3000\right)}^2}{60}$

$=75000J$

$=75kJ$