Learn How to Calculate Radiant Heat Energy using Stefan's Law - Tutorial


Stefan's law states that the total amount of heat energy radiated per second per unit area of an ideal black body is directly proportional to the fourth power of its complete temperature. The constant of proportionality in Stefan's law is the Stefan constant, which is equal to 5.67 * 10-8 W m-2 K-4

Formula :

E α T4 or E = σ T4
σ = Stefan's constant ( 5.67 * 10-8 W m-2 K-4) E = Radiant Energy T = Absolute Temperature
Example :

The sun's surface temperature is 5700K. Calculate the amount of power radiated by one square meter of the sun's surface.

Temperature (T) = 5700k
Stefan's constant (σ) = 5.67 * 10-8 W m-2 K-4
To Find,

Radiant Energy (E)


Substitute given values in the formula,

Radiant Energy (E) = σ T4
= 5.67 * 10-8 * 57004
= 5985252567000000 * 10-8
E = 59852525.67

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