A $6$ m long horizontal pipe.with an outside diameter of $10$ cm$,$ carrying hot water, passes through a room at a temperature of $20\backslash$deg C$.$ The pipe is insulated with a material $($kiaratation $-0\mathrm{.}1$ W$/$m$.$K$)5$ cm thick. The air side surface temperature of the insulation is measured to be $40\backslash$deg C$.$ Under these conditions, the pipe losses heat to air only by natural convection.a$)$Find the convection coefficient on the outer surface of the pipe.b$)$Find the temperature of the surface between the pipe and the insulation$($Tins$).$Physical properties of air at Tr$=30\backslash$deg C:Pr$=0\mathrm{.}72,$ kr$0\mathrm{.}025$ W$/$mK$,$ kinematic viscosity y$=1\mathrm{.}608$x$105$ m$/$s$,$ B$=3,3$x$10$ K$*$l$.$