Solve Momentum Problem: Mass of Gas for Course Correction of 30 Degrees

[pebbles]

Homework Statement

A space probe with mass of 7.60 * 10^3 kg is traveling at 125 m/s. Missions control decides that a course correction of 30 degrees is needed. and instructs probe to fire rockets perpendicular to present direction of motion. If gas expelled by rockets has speed of 3.200 km/s, what mass of gas should be released?

Homework Equations

??

The Attempt at a Solution

3.200 km/s-->3200 m/s

I'm totally stuck on this one. I'm not good at physics, so I need someone to walk me through this problem thoroughly.

Thanks in advance.

 

[CaptainZappo]

Use conservation of momentum considerations.

I can't help you too much because you've shown no attempt at solving this problem on your own.

 

[uber]

Initial Momentum = Final Momentum.

Run with that and see if it gets you anywhere.

 

[pebbles]

uh, I'm confused.
i don't know the final velocity of the rockets...

 

[pebbles]

or wait, would the rockets' initial velocity be zero?

 

[CaptainZappo]

The initial velocity of the gas would be zero with respect to the probe. Consider the total momentum of the proble + gas system. It is this vector quantity that remains unchanged.