OA l-m long hollow cylinder of inner radius 5 cm and outer radius 15 cm is considered. The inner surface is heated uniformly at a constant rate of q = 105W/m². If the inner surface, T1, is maintained at 0°C, calculate the temperature of the outer surface, T2, if K = 75 W /m°C.

Not sure where I went wrong on this please show a drawing also

Mechanical services

40°C water with hwater = 800 W/m² K is flowing in a Pyrex tube. The inner and outer diameters of the tube are 25 mm and 35 mm. A thin metallic heater element bonded to the outer surface of the tube is being used to heat the water by transferring 600 W/m of thermal energy to the water flowing in the tube. The Pyrex tube and heater are covered with a 10-mm thick layer of foam insulation. The outer surface of the foam insulation is exposed to air at T = -5°C with hair = 12 W/m².K. The heater = air element must generate more than 600 W/m, because part of the heat being generated is lost to the air surrounding the foam insulation. Assume kp = 1.30 W/m K for Pyrex and k = 0.026 W/m K for the foam insulation. a) Find the temperature of the heater element needed to transfer 600 W/m of thermal energy to the water in the tube. b) Find the total rate at which the heater element must generate thermal energy. Water Pyrex tube, kp = 1.30 W/m.K = 40°C water hwater = 800 W/m².K Heater element Tair=…