Need Physics Help

[mrSHEiK124]

A 1000 kg satellite orbits the Earth at a constant altitude of 100 km. How much energy must be added to the system to move the satellite into a circular orbit with altitude 200 km? Discuss the changes in kinetic energy, potential energy, and total energy.

All I can understand is that for this kind of system is, KE+ = |1/2PE|

 

[mrSHEiK124]

bump ?

 

[jagec]

There's no way a satellite is going to hold 100 km without constant correction burns. That's a decaying orbit for sure.

Ignoring drag, however, the way you calculate forces is via the elevation change (m*g*delta-d), and kinetic energy can be calculated by balancing the centripetal acceleration due to gravity against the "centrifugal force" provided by various speeds at that orbital radius.

 

[dighn]

what you need:

- speed at given orbit, this will give you the kinetic energy. just solve: gravitional force = centripetal force
- gravitional potential energy at given orbit

just add up the two quantites for each orbit and get the difference. just look up the relevant equations.

 

[mrSHEiK124]

Brain = fart

I think the caffeine from around 11-ish has worn off. I'm going to read all this tomorrow when I'm actually awake.

 

[FleshLight]

Everyone fails.

http://en.wikipedia.org/wiki/Hohmann_transfer_orbit