Question

A 60 kg runner has 1470 J of kinetic energy. How fast is the runner moving?

Answer 1

Given,

The mass of the runner, m=60 kg

The kinetic energy of the runner, K=1470 J

Kinetic energy is the energy possessed by an object due to its motion. And it is given by the formula,

`K=(1)/(2)mv^2`

Where v is the velocity of the runner.

On rearranging the above equation,

`v=\sqrt[]{(2K)/(m)}`

On substituting the known values,

`\begin{gathered} v=\sqrt[]{(2*1470)/(60)} \\ =7\text{ m/s} \end{gathered}`

Thus the speed of the runner is 7 m/s.