I know that the force of gravity is (ma)=GMm/r^2 or a=GM/r^2 This makes sense and If I were to drop a bowling ball down to earth I'd expect it to fall with 9.8m/s^2. However I can calculate that the bowling ball has its own gravity using the formula noted above. My question is what will be the true acceleration of these 2 objects towards each other? Perhaps a better example is the earth and say Jupiter. Would these 2 planets go towards each other at a rate of 25m/s^2(gravity of Jupiter), or perhaps they would go towards each other with 35m/s^2(Gravity of Jupiter+Earth) because the they are both pulling each other in right? So this question seems so simple that any info I've found on it, neglects an explanation. Anyways, thanks!