(I am a newbie in physics. I did not use the template when posting as this isn't really a homework question but about something that makes me confused in elementary physics). Suppose I have two objects (with masses m<M respectively) connected vertically by a wire such that the one with mass m is above. Now I drop this thing and obviously it will speed up with the acceleration g. However, if I look at the forces acting on the smaller object with mass m, there are two forces: the earth's gravitational force mg and the force exerted by the bigger object Mg. So the total net force on the smaller object would be [itex]F=(M+m)g[/itex]. By the Newton's second law, it would accelerate with [itex]a=g(M+m)/m[/itex] This is paradoxical and it confuses me. Can you explain why?