Question

The mass of a rocket car plus fuel is 2,000 kg. The rocket car starts from rest. The engine expels fuel (in the form of exhaust) over a period of 8 seconds. The exhaust has a velocity of 1,000 m/s due west, and the velocity of the rocket after 8 seconds is 90 m/s due east. How much fuel did the rocket car exhaust during the 8 seconds? (Answer is in kg)

Answer 1

momentum is conserved

1000 m/s * x = (2000 - x) * 90 m/s

Answer 2

Thank you sm!!! I have been struggling this for a while and I overcomplicated it!