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,

$K=\frac{1}{2}mv^2$

Where v is the velocity of the runner.

On rearranging the above equation,

$v=\sqrt[]{\frac{2K}{m}}$

On substituting the known values,

$\begin{gathered} v=\sqrt[]{\frac{2\times1470}{60}} \\ =7\text{ m/s} \end{gathered}$

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