Question $1.$ An aluminum cubic block $)=(27k\frac{N}{m^3}$ having dimensions of $0\mathrm{.}500\mathrm{.}500\mathrm{.}50$ slides slowly down a ramp with a constant speed of $4+\frac{a}{10}\frac{m}{s}$ as shown in figure. The uniform$-$thickness of oil layer is $0\mathrm{.}2+\frac{b}{50}mm$ and the angle of the ramp is $45.$ Determine the viscosity of oil assuming that velocity distribution is linear $)=0\mathrm{.}8,{}_{\text{w}\text{a}\text{t}\text{e}\text{r}}=(10k\frac{N}{m^3}$