Satellite problem

[hauthuong]

A 500 kg satellite is in a orbit at an altitude of 500 km above the earth's surface. because of the air friction, the satellite eventually falls to the earth's surface, where it hits the ground with a speed of 2.00 km/s.how much energy was transformed into the internal energy by means of friction?
I really got no clue to solve this one. Could you guy give me some instructions? If you could, give me a lecture about this type of problem. Thank you

[NateTG]

This is a work-energy problem. Consider solving the equation:
KE_0+PE_0=KE_f+PE_f+W_{friction}

[krab]

Take the initial energy (potential plus kinetic) and subtract the final energy.

[hauthuong]

for kinetic energy I will us 1/2mv^2 .How do I find the V initial , Also, for Potential energy , I have to use GM1M2/r2 ??? is it right? Thank you