Question

A car with a mass of 1180 kilograms is being driven at 18.2 meters per second when it runs into a tree. What is the change in kinetic energy of the car? Include units in your answer. Answer my be in 3 significant digits.

Answer 1

The change in kinetic energy of the car can be given as,

`\Delta K=(1)/(2)m(v^2-u^2)`

After running to tree the car will stop therefore, the final speed of car is 0 m/s.

Substitute the knwon values,

`\begin{gathered} \Delta K=(1)/(2)(1180kg)((0m/s)^2-(18.2m/s)^2) \\ =(590\text{ kg)(-}331.24m^2s^(-2))(\frac{1\text{ J}}{1kgm^2s^(-2)}) \\ =-195431.6\text{ J} \\ \approx-195000\text{ J} \end{gathered}`

Thus, the magnitude of change in the kinetic energy of car is 195000 J.