Mathematically, the law of gravitation has the following form nnn F=G (14-1) Here G called the gravitational constant. G=667×10-N·m2(kg)2 We can represent eq(14-1)in vectors form m1m, 12 -C r2 and 21 G=221Eq(143) where r2 and r are unit vectorsMathematically, the law of gravitation has the following form (14-1) Here G, called the gravitational constant. We can represent Eq(14-1) in vector’s form. where and are unit vectors. 2 1 2 r m m F = G 11 2 2 G = 6.6710 N m /(k g) − →  = − 2 21 21 1 2 21 r r m m F G →  = − 2 12 12 1 2 12 r r m m F G and  21 r  12 r Eq(14-3)