Physics

Problem

A runner moves

4\,\text{m/s}

east relative to a flatcar. The flatcar moves

10\,\text{m/s}

west relative to a train, and the train moves

12\,\text{m/s}

east relative to the ground. What is the runner’s speed relative to the ground? a)

2\,\text{m/s}

west b)

6\,\text{m/s}

east c)

6\,\text{m/s}

west d)

2\,\text{m/s}

east