In Case A the mass of each block is 4.9 kg. In Case B the mass of block 1 (the block behind) is 9.8 kg, and the mass of block 2 is 4.9 kg. No frictional force acts on block 1 in either Case A or Case B. However, a kinetic frictional force of 9.6 N does act on block 2 in both cases and opposes the motion. For both Case A and Case B determine (a) the magnitude of the forces with which the blocks push against each other and (b) the magnitude of the acceleration of the blocks.