Physics · Oct / Nov 2025 · Paper 12 · Question 16

A rocket has mass M when empty. The rocket carries an additional mass M of fuel. The rocket and fuel travel at a speed v. When the engine of the rocket is fired, all of the fuel is expelled and the speed of the rocket increases to 2v. What happens to the kinetic energy of the rocket?

1. AIt doubles.
2. BIt halves.
3. CIt increases by a factor of four.
4. DIt stays the same.

As printed in the paper