Question

A 60 kg runner has 480 J of kinetic energy. How fast is the runner moving?

Answer 1

Given that the mass of the runner, m = 60 kg

The kinetic energy of the runner, K.E. = 480 J

To find the speed of the runner, v

Kinetic energy is given by the formula

`K\mathrm{}E\mathrm{}=\text{ }(1)/(2)mv^2`

Substituting the known values, speed will be

`\begin{gathered} v=\sqrt[]{(2* K.E.)/(m)} \\ =\sqrt[]{(2*480)/(60)} \\ =4\text{ m/s} \end{gathered}`

Thus the speed of the runner is 4 m/s.