Consider a flat$-$plate solar collector placed horizontally on the flat roof of a house. The collector is $5$ ft wide, $15$ ft long, and the average temperature of the exposed surface of the collector is $110$F$.$ The emissivity of the exposed surface of the collector is $0\mathrm{.}9.$ Determine the rate of heat loss from the collector by convection and radiation during a calm day when the ambient air temperature is $75$F and the effective sky temperature for radiation exchange is $55$F$.$ Take the convection heat transfer coefficient on the exposed surface to be $3\mathrm{.}0$ Btu$/$h$.$ft$2.$F$.[$MO $1\mathrm{.}4,$ MO $1\mathrm{.}6,$ MO $1\mathrm{.}7$