Question $3.$ For the following processes write down the model equations.

i$)$

ii$)$

Question $4.$ A fluid of constant density $(k\frac{g}{m^3})$ is pumped into a cone$-$shaped tank of total volume $H\frac{R^2}{3}.$ The flow of the bottom of the tank is proportional to the height $h$ of liquid in the tank. Derive the dynamic model for the system.