Two blocks are in contact on a frictionless table...?

Two blocks are in contact on a frictionless table. A horizontal force is applied to the larger block, as shown in Fig. 5-51. (a) If m1 = 2.2 kg, m2 = 1.3 kg, and F = 2.9 N, find the magnitude of the force between the two blocks. (b) ume instead that a force of the same magnitude F is applied to the smaller block but in the opposite direction, and calculate the magnitude of the force between the blocks. (Why is the value calculated in (b) not the same as that calculated in (a)?)