An infinitely long rod (k= 200 Wm-'K-?) has a diameter of 40 mm. It is split in two halves, with one half of it exposed to ambient air at a temperature (T.,1) of 20 °C and a convective heat transfer coefficient (hi) of 5 Wm²K-1, and the other half of it exposed to water at a temperature (T.,2) of 15 °C and a convective heat transfer coefficient (h2) of 10 Wm-K-1 Joule heaters apply a heat rate (gb) to the rods at the air/water interface which then dissipates in both directions along the length of the rod. Determine the heat rate (9b) if temperature of the rods at their base (Tb) is 40°C. Assume that the surface emissivity of the rod is negligible. d= 40 mm k= 200 Wm-1K1 Air Toy = 20°C hy = 5 Wm-2K-1 91.1 Heater, 9. = ? 914.2 To = 40 °C Water T.2= 15°C ha= 10 Wm-2K-1