The average heat transfer co efficient for flow of 100^o C air over a flat plate is calculated by observing the temperature time history of a 3mm thick copper slab exposed 100^o C air. In one test run, the initial temperature of the plate was 210 ^oC, and in 5 minutes the temperature decreased by 40 ^oC. Determine the heat transfer coefficient for this case. Also derive the equation used to determine heat transfer coefficient. Take the following properties of copper ρ = 8800kg/m³ , Cp = 400J/Kg^oC