this is not fluid mechanic question it is mathematical modelling question please derive equation do not copy paste please. thank you.

a Question 1: As shown in the figure, a fluid flows down through a slit formed between two parallel walls with a distance of 2B between them. The inlet pressure of the fluid is P, and the outlet pressure is Pl. Derive for the steady-state conditions: a) The velocity profile b) The equation for the maximum velocity W