## Homework Statement

a 1.0*10^4kg spacecraft is traveling through space with a speed of 1200 m/s realtive to earth. a thruster fires for 2.0 min, exerting a continuous force of 25kN on the space craft in a direction opposite the spacecrafts motion . calculate the initial momentum and the fianl momentum kof the spacecraft.

## The Attempt at a Solution

G01
Homework Helper
Gold Member
You need to show work here in order to get help. Those are the rules. What have you tried so far? What are you thoughts on the problem?

(-25*10^3)(2.0)=(1.0x10^4)(1200)+(1.0*10^4)(mvi)

G01
Homework Helper
Gold Member
OK. Your big problem is with units. You have seconds on one side of the equation and minutes on the other side of the equation.

Also, remember the equation is:

Impulse =Change in Momentum.
$$J=\Delta p=p_f-p_i$$

Last edited:
ok so it would be 120s instead of 2.0min

(-25*10^3)(120)= (1.0*10^4)(mvi)-(1.0x10^4)(1200)

G01
Homework Helper
Gold Member
(-25*10^3)(120)= (1.0*10^4)(mvi)-(1.0x10^4)(1200)

That looks good to me.