During air cooling of oranges, grapefruit, and tangelos, the heat transfer coefficient for...

During air cooling of oranges, grapefruit, and tangelos, the heat transfer coefficient for combined convection, radiation, and evaporation for air velocities of 0.11 < V < 0.33 m/s is determined experimentally and is expressed as h = 5.05 k_airRe^1/3/D, where the diameter D is the characteristic length. Oranges are cooled by refrigerated air at 5°C and 1 atm at a velocity of 0.3 m/s. Determine (a) the initial rate of heat transfer from a 7-cm-diameter orange initially at 15°C with a thermal conductivity of 0.50 W/m·K, (b) the value of the initial temperature gradient inside the orange at the surface, and (c) the value of the Nusselt number.