E $9\mathrm{.}35.$ The drag on a ship $122$ m long and with $2135m^2$ wetted area is to be estimated. A model towed at $1\mathrm{.}3\frac{m}{s}$ through fresh water had a total drag resistance at $15\mathrm{.}3$ N $.$ The skin resistance was separately analyzed and found to follow the law $F=c{u}_m^{1\mathrm{.}9}.$ When tested at $3\frac{m}{s},$

the skin resistance was $14\mathrm{.}33N{m}^2$ and the ships skin resistance is estimated to follow the law F$=c{u}_u^{1\mathrm{.}85}$ and has a value of $43\frac{N}{m^2}.$ Determine the corresponding speed of the ship and the power needed to propel it$.$ Density of the sea water is $1025\frac{kg}{m^3}$

Answers:$(7\mathrm{.}51\frac{m}{s},6530kW$