The formula for the velocity of a body in a circular orbit at distance "r" from the center of gravity of mass "M" is:formula_10where formula_11 is the gravitational constant, equal to: 6.673 84 × 10−11 m3/(kg·s2)To properly use this formula, the units must be consistent; for example, "M" must be in kilograms, and "r" must be in meters.