Determine the percentage increase in heat transfer associated with attaching aluminum fıns of rectangular profile to a plane wall.The fins are 50 mm long. 0.5 mm thick, and are equally

spaced at a distance of 4.00 mm (250 fins/m). The convection coefficient associated with the bare wall is 40 W/m2 K, while that resulting from attachment of the fins is 30 W/m2-K.