Question

A moving body of mass $10kg$ has $20J$ of kinetic energy. Calculate its speed.

Answer 1

Step 1- Given data :

Mass of moving body $m=10kg$

Kinetic energy $K.E.=20J$

Step 2- Calculation of speed.

Use the formula of Kinetic energy.

That is,

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

Here $v$ is the velocity.

Substituting the values in the equation.

$$\begin{gathered} 20J=\frac{1}{2}\times 10kg\times v^2 \\ {v}^2=\frac{20\times 2}{10} \\ {v}^2=4 \\ v=2m{s}^{-1} \end{gathered}$$

Hence, the speed of a moving body is $2m{s}^{-1}.$