# Energy of Satellites(Homework question)

1. Apr 27, 2015

Hi,

1.
I have a question all based upon a 100kg satellite in orbit 620km above Earth's surface,
I need to find the total energy (at rest), kinetic energy (in orbit), and binding energy (in orbit) of said satellite.

2.
I have tried to get the answer for the kinetic energy in orbit using:
1/2mv^2 = Total Kinetic Energy

I believe this is correct, getting the velocity by using the satellite motion formula v = sqrt[(GM)/r], where r is the radius of the earth + the distance the satellite is from the earth's surface.

3.
1/2(100kg){sqrt[(2GM)/r]}^2 = Total Kinetic Energy
1/2(100kg)[(6.67 x 10^{-11} x 5.98 x 10^{24}kg) / (6.38 x 10^{6}m + 620'000m)]
Total Kinetic Energy = 2.85 x 10^{9} Joules
(is this correct???)

However, I'm having trouble grasping how to get total energy and binding energy.
Could someone explain binding energy to me in terms of a satellite in orbit?

I understand the total energy during orbit will involve kinetic energy, but it asks for energy at rest and I'm not sure which type of energy it has during this time? Is it grav. potential energy?

Any help would be appreciated, thank you.

2. Apr 27, 2015