posted by Sarah on .
The mass of a rocket car plus fuel is 2,000kg. 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 1,000m/s due west, and the velocity of the rocket car after 8 seconds is 90m/s due east. How much fuel did the rocket car exhaust during the 8 seconds?