Particles of masses m1 and m2 are at a fixed distance apart. If the gravitational field strength at m1 and m2 are l1 and l2 respectively. Then:
Let L1 and L2 be two non-vertical lines with slopes m1 and m2 respectively. If α1 and α2 are the inclinations of lines L1 and L2, respectively. the acute angle (say θ) between lines L1 and L2 , is given by