A rocket coasts in deep space with no external forces acting on it

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

Problem

2000\,\text{kg}

rocket coasts in deep space with no external forces acting on it. It ejects

100\,\text{kg}

of exhaust gas in

2.0\,\text{s}

at a speed of

500\,\text{m/s}

relative to the rocket. Immediately after the exhaust is expelled, what is the rocket’s average acceleration during the

2.0\,\text{s}

interval? (a)

25\,\text{m/s}^2

(b)

12.5\,\text{m/s}^2

(c)

0\,\text{m/s}^2

(d)

13.2\,\text{m/s}^2