Some physics/math help

[Kristian Calhoun]

When we learned about satellite motion in my physics class last year, to find velocity at a certain altitude we used the equation

v = sqrt(G*m/r)

Where G is the gravitational constant, 6.67x 10^-11 Nm²/kg²
m is the mass (kg) of the body/planet the satellite is orbiting, and r is the radius (altitude) of orbit in meters.

You could use the given distances to find the velocity at each altitude, subtract your answers to find the change, and convert to the proper units.