In a study to examine the heat transfer mechanism, A metal box 90 cm long, 25 cm wide and 7.65 cm deep is advanced at a speed of 22.34 m/s. The box has a surface temperature of 63 C with an ambient temperature of 2 C. Calculate the rate of heat flow through the box. Note 1: Make sure that the bottom of the box is not exposed to air so it will not lose heat. Note 2: With the assumption of a turbulent nerve layer, the same convective for all sides of the box Use the heat transfer coefficient.

=1.07 kg/m3

= viscosity=1.99 x10-5 Pa.sec

Pr=0.707 k= 0.02667 W/m K (Thermal conductivity of air at 32.5 C)