A thick-walled tube of stainless steel(Ks=19.0 W/m.°C)  with 2-cm inner diameter (ID) and 4-cm outer diameter (OD) is covered with a 3-cm layer of asbestos insulation (ka =0.2 W/m.°C). If the temperatures of  inside wall of the pipe and the outside of the insulator are maintained at 600 and the surface temperature on the insulating material remained constant at 293 °C.  determine the values of r1,r2,and r3 from the below equation and calculate heat loss per unit lenght . q/L​=ln(r2​/r1​)/Ks​+ln(r3​/r2​)/Ka​2π(T1​−T2​)​

A 10 cm thick piece of beef steak will be frozen in the freezer room -40 ° C. This product has a moisture content of 73%, a density of 970 kg / m³, and a thermal conductivity (frozen) of 1.1 W / (m K). Estimate the freezing time. using the Plank equation. This product has an initial freezing temperature of -1.75 ° C, and the movement of air in the freezing room gives a convective heat transfer coefficient of 15 W / (m² K). t f =       hour

Heat Conduction The wall (thickness L) of a furnace, with inside temperature 800° C, is comprised of brick material [thermal conductivity = 0.02 W m-¹ K-¹)]. Given that the wall thickness is 12 cm, the atmospheric temperature is 0° C, the density and heat capacity of the brick material are 1.9 gm cm-³ and 6.0 J kg ¹ K¹ respectively, estimate the temperature profile within the brick wall after 2 hours. Solve the partial differential equation ƏT = pc at Ə əx (NOT) k subject to the initial condition TX 2L and = T(x,0) = 800 sin and boundary conditions at the inner (x = L) and outer (x = 0) walls of T = 0 x = 0 = 0 ƏT at x = L əx Find the temperature profile at T = 7200 seconds at = 2 hours.

(a) What is the heat loss per unit length of the pipe?(b) The pipe material is switched to PTFE (k = 0.38 W/(m⋅K)). To maintain the same heat loss as theprevious question, if all other parameters are to remain the same as before, what is the required thicknessof the pipe wall in centimeters?