Three blocks of mass 12.5 kg each, on a frictionless horizontal surface are in contact with each other as shown in the figure below. A force F = 91.4 N is applied to block 1 (mass m1). Determine the acceleration of the system (in terms of m1, m2, and m3). I did 91.4 = 12.5a 91.4/12.5 = 7.312 but something is missing to that equation. how do I do it in terms of m1, m2, and m3)?