Physics

Problem

A runner covers

120\,\text{m}

east in

15\,\text{s}

and then

80\,\text{m}

west in

20\,\text{s}

. What is the runner’s average speed for the whole motion? a)

4.0\,\text{m/s}

6.0\,\text{m/s}

5.7\,\text{m/s}

3.4\,\text{m/s}