Physics

Problem

A train is running at

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

. The driver first reduces the speed by applying a retardation of

1\,\text{m s}^{-2}

for the next

200\,\text{m}

and then increases the braking so that a retardation of

2\,\text{m s}^{-2}

acts until the train stops. The total distance travelled after the brakes were first applied is closest to a)

300\,\text{m}

256\,\text{m}

200\,\text{m}

312.5\,\text{m}