1. The problem statement, all variables and given/known data A thin flat plate 2m×2m is hanging freely in air. The temperature of the surroundings is 25°C. Solar radiation is falling on one side of the plate at the rate of 500 W/m2. What should be the convective heat transfer coefficient in W/m2°C, if the temperature of the plate is to remain constant at 30°C? A 25 B 50 2. Relevant equations There are 2 version 3. The attempt at a solution First version:500x4=2(hx4x5) h=50 Second version: 500=hx4x5 h=25 3 authors gave 25 as the answer, while 1 author gave 50 as the answer. I personally felt 50 is the correct solution as radiation is in 500W/m^2 not 500W, also taking into account convection on both sides, with radiation only on one side. Can anyone clarify what is the real answer? Which version should i believe?