help with number 2?

1) (25 pts) Cooling a Computer Chip with a Fan A square computer graphics chip measures 5.0cm per side and is 3.0mm thick. The chip consumes 15W of power which is dissipated as heat. It is packaged into a ceramic device in a way which only allows transfer of heat from the top side of the chip (insulated on all other sides). A fan blows air over the surface of the chip to promote convective heat transfer of the heat generated by chip. Unfortunately, the chip fails to operate after a certain time, and the temperature of the chip is suspected to be the culprit. REQUIREMENT: To achieve an acceptable chip failure rate of less than 5% the chip surface temperature