When a horizontal force of 4.5 newtons acts on a block on a resistance-free surface, it produces an acceleration of 2.5 m/s squared. Suppose a second 4.0 kg block is dropped onto the first. What is the magnitude of the acceleration of the combination if the same force continues to act? Assume that the second block does not slide on the first block.

Answer 1

first block=F=ma , but this same force acts after the second block is dropped.

F=(m+M)a' = ma
solve for a'