A tank $1\mathrm{.}2m$ diameter and $2m$ high is filled to a depth of $1\mathrm{.}2m$ with a

latex having a viscosity of $10P$ and a density of $800k\frac{g}{m^3}.$ The tank is

not baffled. A three$-$blade $360-$mm$-$diameter propeller is installed in the

tank $360mm$ from the bottom. The pitch is $1$:$1($pitch equals diameter$).$

The motor available develops $8kW.$

$9\mathrm{.}1$ Is the motor adequate to drive this agitator at a speed of $800\frac{r}{m}in?$

$9\mathrm{.}2$ What is the maximum speed at which the agitator of the tank may be

driven if the liquid is replaced by one having a viscosity of $1P$ and the

same density?An oil having a density of $833k\frac{g}{m^3}$ and a viscosity of $3\mathrm{.}3{10}^{-3}Pa*s$

is pumped from an open tank to a pressurised tank held at $345$kPa

gage. The oil is pumped from an inlet at the side of the open tank

through a line of commercial steel pipe having an inside diameter of

$0\mathrm{.}07792m$ at the rate of $3\mathrm{.}494{10}^{-3}\frac{m^3}{s}.$ The length of straight pipe

is $122m,$ and the pipe contains two $90$ elbows and a globe valve half

open. The level of the liquid in the open tank is $20m$ above the liquid

level in the pressurised tank. The pump efficiency is $65\%.$ Calculate

the $kW$ power of the pump.