A 6090kg space probe mobing nose-first toward Jupiter at 105m/s relative to the Sun, fires its rocket engine ejecting 80 kg of exhaust at a speed of 253 m/s relative to the space probe. What is the final velocity of the probe?

I should have gotten 108m/s Can you show me the correct way to solve this problem? Thanks so much for your time and effort. I really would apprecitate it!

Momentum:

80(253)=(6090-80)delta v
deltav=?
This is an approximation. A better solution is to take the average mass of the spacecraft as (6090-80/4), but it wont matter much.

There is an exact method in Calculus, but I assume you are not a calculus person.

1 answer

Conservation of momentum:

6090(105) = 80(-253) + 6010(Vf)

Vf = 109.77 m/s