(SOLVED) Space Shuttle launches a satellite

[pinkybear]

Homework Statement

The space shuttle launches an 890-kg satellite by ejecting it from the cargo bay. The ejection mechanism is activated and is in contact with the satellite for 3.0 seconds to give it a velocity of 0.20 m/s in the z-direction relative to the shuttle. The mass of the shuttle is 9.5×10^4kg.

Determine the component of velocity of the shuttle in the minus z-direction resulting from the ejection.

Find the average force that the shuttle exerts on the satellite during the ejection.

Homework Equations

m1v1 = m1v2 + m2v3
(1/2)mv*2 = (1/2)mv^2 + (1/2)mv^2
W=FD=KE

The Attempt at a Solution

I don't know where to start.. i can get the acceleration of the satellite i guess using the v=v(0)+at..since I have the mass of the satellite using f=MA..then the force of the satellite (right?) but how do I get the shuttle velocity?
I don't know what the z direction is or vf of the shuttle? is it the opposite of the satellite because it is pushing against it? I'm not sure..

oh nevermind, I got it =D that was right ^ and for the velocity of the shuttle I used the 1st equation: m1v(f)1=m2v(f)2

 

[jbsteele]

+ m1v(i)1v(f)1 = (m2v(f)2 + m1v(i)1)/m1 = (890*0.20 + 9.5*10^4*0)/(9.5*10^4) = 0.02 m/s in the minus z direction