You go and choose a solid chemical rocket which expels gas from the engine at 3 kilometers per second. The rocket has a total mass of 2 kg with the fuel being 1 kg. The theoretical maximum speed of this rocket is:

1500 m/s

Explanation:

From Newton's Third law of motion,

Momentum of the hot gas = Momentum of the rocket

mv = MV ... Equation 1

Where m = mass of the fuel, v = velocity of the gas, M = mass of the rocket, V = velocity of the rocket.

Making V the subject of the equation

V = mv/M ... Equation 2

Given: m = 1 kg, M = 2 kg, v = 3 km/s.

Substituting into equation 2

V = 1 (3) / 2

V = 3/2

V = 1.5 km/s

V = 1500 m/s

Hence the maximum speed of the rocket = 1500 m/s