Problem $4(20$ points$)$: Heat transfer from an atmospheric air $(T_{}=10C)$ that is flowing at rate of $55\frac{m}{s}$ over a flat plate with an extremely rough surface can be correlated with the following expression ${}_x=0\mathrm{.}0395R{e}^{0\mathrm{.}987}P{r}^{0\mathrm{.}345}.$ Determine the shear stress at $x=1\mathrm{.}25m$ from the leading edge of the plate. If the plate is maintained at a temperature of $85C$ through an electric heater and plate surface area is $0\mathrm{.}35m^2,$ determine the electrical power of the heater.