3. (25 Points) A block of mass mi is placed on top of a block of mass m2. You push the two blocks, so that they move up a vertical wall, with a constant force of magnitude P directed at the angle 0 as shown. The coefficient of friction between the block of mass m2 and the wall is . There is no friction between the blocks and no friction between block m1 and the wall. Find the force exerted by the lower block on the upper block. Law or Definition Application