A sheet of styrofoam of thickness 2 cm and area 0.1 m2 has a temperature difference of 30°C between its inner and outer surfaces. Considering thermal conductivity as 0.01 J/s m K, the rate of heat flow through the sheet is:
1
3.0 J/s
2
2.0 J/s
3
1.0 J/s
4
1.5 J/s