Physics

Problem

In which of the following cases is the average velocity of the motion zero while the average speed is NOT zero? a) Walking

400\,\text{m}

straight north and stopping there in

4\,\text{min}

b) Walking

400\,\text{m}

around a circular track and stopping at the starting point in

4\,\text{min}

c) Walking

400\,\text{m}

around a semicircular track and stopping at the opposite side in

4\,\text{min}

d) Walking

200\,\text{m}

east and then

200\,\text{m}

north and stopping there in

4\,\text{min}