Question 12 5 pts Calculate the rate at which energy is radiated from a black surface, 0.3 m^2 in area, which is white hot at 1500 °C. The Stefan-Boltzmann constant is ? = 5.67 x 10^-8 W m^-2 K^4 168 kW 5.34 x 10^-5 kW 560 W 145 W 112 kW Question 13 5 pts The surface temperature of an insulated steam main is 45 °C and the surrounding air temperature is 18 °C. Assume that the surroundings are completely absorbing (i.e. the black body assumption) and the Stefan-Boltzmann constant is 5.67 x 10^-8. What will be the heat loss per area by radiation from the insulated steam main, if the emissivity of the surface of the insulation is 0.9? 145.75 W m^-2 173.23 W m^-2 87.08 W m^-2 155.91 W m^-2 200.56 W m^-2
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3 m^2), the temperature of the surface (1500°C), and the Stefan-Boltzmann constant (σ = 5.67 x 10^-8 W m^-2 K^-4). The rate at which energy is radiated from a black surface can be calculated using the Stefan-Boltzmann law: P = σ * A * T^4 where P is the power Show more…
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