A horizontal force of 38 acting on a block on a frictionless, level surface produces an acceleration of 2.4 .?

A horizontal force of 38 acting on a block on a frictionless, level surface produces an acceleration of 2.4 . A second block, with a mass of 4.3 , is dropped onto the first.What is the magnitude of the acceleration of the combination of blocks if the same force continues to act? (Assume that the second block does not slide on the first block.)