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kerbyjonsonjr
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Homework Statement
A 6000 kg lunar lander is in orbit 80 km above the surface of the moon. It needs to move out to a 200 km -high orbit in order to link up with the mother ship that will take the astronauts home.
How much work must the thrusters do?
Homework Equations
v=[tex]\sqrt{}GM/r[/tex]
W=[tex]\Delta[/tex]KE
G=6.67 x10-11
Radius of moon= 1,737.4 km
Mass of moon=7.36 x1022
The Attempt at a Solution
Since W=change in KE I figured I would just find the velocity before and after then plug it in. I used v=sqrt GM/r so sqrt 6.67 x10-22* 7.36 x1022/(1737.4+80) and got 51,972.9 m/s and then I did that again with the radius being 1,737.4+200 and got v= 50,337.7 m/s
Then I solved for change in KE=1/2mv2 so 1/2(6000)(50377.72) -1/2(6000)(51972.92) and got -5.02 x1011
I am not sure where I messed up but I know my answer is wrong. Any help would really be great.