Cartridge electrical heater is shaped as a cylinder of length L 200 mm and outer diameter D 20 mm. Under normal operating conditions, the heater dissipates 2 kW while submerged in a water flow that is at 20 C and provides a convection heat transfer coefficient of h 5000 W/m2 K. Neglecting heat transfer from the ends of the heater, determine its surface temperature Ts. If the water flow is inadvertently terminated while the heater continues to operate, the heater surface is exposed to air that is also at 20 C but for which h 50 W/m2 K. What is the corresponding surface temperature