$($a$)$ Describe the rheology of the major classes of time independent fluids. Refer to a labelled diagram.

$($b$)$ Oil flows through a $50mm$ diameter pipe attached to a horizontal Venturi meter with a throat diameter of $10mm.$ The oil density is $900kg{m}^{-3}$ and the pressure drop over the converging section of the Venturi is $80mm.$ If the coefficient of discharge for the Venturi is $0\mathrm{.}92$ and acceleration due to gravity is $9\mathrm{.}81m{s}^{-2},$ determine the flow rate of oil through the pipe.

$(6)$

You may use the formula:

$Q=C_d{A}_1\{\frac{2gh}{(\frac{A_1}{A_2}{)}^2-1}{\}}^{\frac{1}{2}}$

Where: $A_1$ is the pipe diameter and the other symbols have their usual meanings.