Air at a temperature of 333 °C flows with a velocity of 10 m/s over a flat plate 0.5m long. Estimate the cooling rate per unit width of the plate needed to maintain the plate at a surface temperature of 27 °C. Properties of air: kinematic viscosity 5.21×10-4 m2/s, thermal conductivity 36.4×10-3 W/m∙K, Prandtl number 0.687.