A 15cm x 20cm printed circuit board is to be cooled by passing cool air through a 20 cm long channel of rectangular cross section 0.2 cm x 14 cm drilled into the board. The heat generated by the electronics components is conducted across the thin layer of the board to the channel where it is removed by air that enters the channel at 15oC. The heat flux at the top surface of the channel can be considered to be uniform and heat transfer through other surfaces is negligible. If the velocity of the air at the inlet of the channel is not to exceed 4m/s and the surface temperature of the channel is to remain under 50oC, determine the maximum total power of the electronic components that can safely be counted on this circuit board.