Question

The Stefan-Boltzmann law can be employed to estimate the rate of radiant energy loss from a surface, as in H = AeoT4 where H is in watts, A = the surface area (m2), e = the emissivity (dimensionless quantity that characterizes the rate of heat loss from a material versus a perfect radiator, or blackbody radiator), σ = the Stefan-Boltzmann constant (5.670367 × 10-8 W·m「"K-4), and T = absolute temperature (K). a) Employ equation (4.25) from the text to estimate the error in H given a steel plate with A = 0.15 m2, e = 0.881, and T = 650 ± 20°K. Compare your result with the exact answer and find . b) Repeat the calculation in part a) for T = 650 ± 40 %. Compare your result with the exact answer and find t. c) Employ equation (4.27) from the text to estimate the error in H given a steel plate with A = 0.15 ± 0.01 m2, e = 0.881 ± 0.009, and T = 550 ± 20°K. Compare your result with the exact answer and find the maximum

eq 4.25

eq 4.27

Answer 1

d T 二 8.23111 8890,- 161 62937 1331 61