A $20-$cm$-$diameter cylinder

rotates inside a stationary

$20\mathrm{.}2$ am$-$diameter cylinder

at $=150rpm$ due to a

torque of $20$ Nm $.$ The gap

is filled with a liquid

Given: $=\frac{du}{dr}$

$T=F_r.,P=UF$

What is the dissipzted power, $P?$

$\{\begin{array}{c}\text{:}F=\frac{T}{R}=\frac{20}{0\mathrm{.}1}=200N=A=>2RL\end{array}$

What is the viscosity of the liquid in the gap

between the two cylinders?

$=\frac{200}{2**0\mathrm{.}1**0\mathrm{.}5}=637P_2$

$=\frac{du}{dr}=\frac{u}{b}-\frac{b}{u}=\frac{0\mathrm{.}001**637}{1\mathrm{.}57}=0\mathrm{.}406P_{2\mathrm{.}3}$

$U=R=150**0\mathrm{.}1**\frac{2}{60}=1\mathrm{.}57\frac{m}{s}$

Please solve for me im not sure if I did it right or wrong