Consider a circular furnace that is \(0.5 \mathrm{~m}\) long and \(0.5 \mathrm{~m}\) in diameter. The two ends have diffuse, gray surfaces that are maintained at 400 and \(500 \mathrm{~K}\) with emissivities of 0.4 and 0.5 , respectively. The lateral surface is also diffuse and gray with an emissivity of 0.7 and a temperature of \(800 \mathrm{~K}\). Determine the net radiative heat transfer rate from each of the surfaces.