An object of weight W is dropped onto the midpoint of a simple beam AB from a

Question:

An object of weight W is dropped onto the midpoint of a simple beam AB from a height h (see figure). The beam has a rectangular cross-section of area A. Assuming that h is very large compared to the deflection of the beam when the weight W is applied statically, obtain a formula for the maximum bending stress σ_max in the beam due to the falling weight.