GAL: Gradient Adaptive Lattice: GAL: Guggenheim Aeronautical Laboratory: GAL: Gas Analysis Laboratory: GAL: George A. Lincoln (WWII General) Gal: Galindian (linguistics) GAL: Guinea Airways, Ltd. GAL: Groupe Antiterroristes de LibÃ©ration (French: Anti-Terrorist Liberation Group) GAL: Gathering Arm Loader (mining) GAL: Graphics Adapter Language: GAL: Gimbal Angle Loss: GAL
1 If the distance between two magnets is doubled the magnetic force between them will fall to a quarter of the initial value. #(F//4)#.  If the distance between two magnets is halved the magnetic force between them will increase to four times the initial value. #(4F)#.
At the subduction zone, when the density of the plate increases, the plate tends to subduct more, and with its subduction it pulls the tectonic plates and hence drives its movement. The increase in density is because of the phase change of many minerals in the subducting tectonic plate. Hope this answers your question.