What must be the orbital speed of a satellite in a circular orbit 740 km above the surface of the earth?

Answer 1

The distance from the center of the earth will be
R = 740 + Re
= 6380 = 7120 km = 7.12*10^6 m

GMm/R^2 = mV^2/R

V = sqrt(GM/R)
G is the universal gravity constant and M is the mass of the earth. Solve for V