A train moving at is brought to rest by applying brakes and travels before stopping

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

Problem

A train moving at

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

is brought to rest by applying brakes and travels

100\,\text{m}

before stopping. Assuming uniform retardation, what is the magnitude of its acceleration? (a)

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

(b)

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

(c)

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

(d)

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