Question

A body of mass $50\mathrm{kg}$ has a momentum of $3000\mathrm{kg}{\mathrm{ms}}^{-1}$. Calculate :
the kinetic energy of the body.

Answer 1

Step 1: Given data

Mass of a body, $m=50Kg$

Momentum $\rho =3000Kgm{s}^{-1}$

Step 2: Formula & solution

$momentum=mass\left(m\right)\times velocity\left(v\right)$

Thus the velocity of the body will be $v=\frac{\rho }{m}$

substitute the given value in the above equation of velocity we get,

$v=\frac{3000}{50}=60m{s}^{-1}$

Step 3: Kinetic Energy of the body

$K.E=\frac{1}{2}m{v}^2$

Substitute the value in the above Kinetic energy equation we get,

$$\begin{gathered} K.E=\frac{1}{2}\times 50\times {60}^2=25\times 60\times 60 \\ K.E=25\times 3600=90,000J \end{gathered}$$

Hence the kinetic energy of the body is $90,000J$.