Inside a train moving east

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

Inside a train moving east, a child walks

1.5\,\text{m/s}

toward the rear (west) measured relative to the train. An observer standing on the ground sees the child moving

0.5\,\text{m/s}

east. What is the speed of the train relative to the ground? (a)

1.0\,\text{m/s}

west (b)

2.0\,\text{m/s}

west (c)

2.0\,\text{m/s}

east (d)

1.0\,\text{m/s}

east