# Satellite moving in a stable circular orbit

by ronartest
Tags: circular, moving, orbit, satellite, stable
 HW Helper P: 2,155 Would you attempt to do this problem without knowing how to multiply? Because that's just what you did. You really can't expect to be able to solve physics problems without knowing how to do basic math, and that includes both numbers and units. So what are the units on the gravitational force you calculated? $$F = G\frac{m_1 m_2}{r^2}$$ You're right that G has units of N m^2/kg^2 (it's lowercase m for meters, not capital M), and both m1 and m2 have units of kilograms, and that r has units of kilometers (but note that r is squared in the denominator). How would you figure out the result of multiplying (N m^2/kg^2) * kg * kg / km^2?