Physics

Problem

A car travels

50\,\text{km}

due north in

1.0\,\text{h}

and then

30\,\text{km}

due south in

45\,\text{min}

. What is the magnitude of its average velocity for the whole trip? a)

28.6\,\text{km}\,\text{h}^{-1}

45.7\,\text{km}\,\text{h}^{-1}

11.4\,\text{km}\,\text{h}^{-1}

13.8\,\text{km}\,\text{h}^{-1}