Rate of energy flow in radiation (14-22)

Question 1 of 5

Question

Surface area of the object

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Question

Stefan-Boltzmann constant = $5.6704 \times 10^{-8}8 \mathrm{W} \cdot \mathrm{m}^{-2} \cdot \mathrm{K}^{-4}$

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Review

Experiment shows that any object emits energy in the form of radiation. The rate at which radiation is emitted by an object—that is, the radiated power $P$ in joules per second or watts—is proportional to the object’s surface area $A$ and to the fourth power of the Kelvin temperature $T$ of the object:

The Stefan-Boltzmann constant $\sigma$ (the Greek letter sigma) has the same value for all objects. The quantity $e$ is the emissivity of the surface; its value indicates how well or how poorly a surface radiates. A surface with a value of $e$ close to 1 is a good radiator of thermal energy.