# Help with physics home work

1. Dec 21, 2008

### Farcry25

1. The problem statement, all variables and given/known data
A space probe with a mass of 7.660 103 kg is traveling through space at 110 m/s. Mission control decides that a course correction of 30.0° is needed and instructs the probe to fire rockets perpendicular to its present direction of motion. If the gas expelled by the rockets has a speed of 3.200 km/s, what mass of gas should be released?

2. Relevant equations
i dont know thats what i need help on, i have no idea what equations to use for this its the only problem on my home work that makes no sense to me, some one please help me

2. Dec 21, 2008

### glueball8

What method should you approch this question?

3. Dec 21, 2008

### Farcry25

i have no idea man i know it has something to do with the conservation of momentum but i dont know much more

4. Dec 21, 2008

### pentazoid

I think you should determined the relationship between the initial momentum and the final momentum and I think from there, you can determine the mass of the expelled gas. Think about the law of conservation for linear momentum.

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