Stefan-Boltzmann Calculator
Calculate thermal radiation power using the Stefan-Boltzmann law: P = epsilon * sigma * A * T^4.
Radiated Power
56,704.00 W
Radiated Power vs Emissivity (0-1)
Fórmula
## Stefan-Boltzmann Law Every object radiates thermal energy proportional to the fourth power of its temperature. ### Formula **P = epsilon * sigma * A * T^4** where sigma = 5.6704 x 10^-8 W/(m²·K^4) is the Stefan-Boltzmann constant and epsilon is the emissivity (1 for a perfect black body).
Ejemplo Resuelto
A perfect black body (epsilon=1) at 1000 K with 1 m² surface area.
- 01P = epsilon * sigma * A * T^4
- 02P = 1 * 5.6704e-8 * 1 * 1000^4
- 03P = 5.6704e-8 * 1e12
- 04P = 56,704 W = 56.7 kW
Preguntas Frecuentes
Why does radiation scale with T to the fourth power?
This comes from integrating the Planck radiation spectrum over all wavelengths. Small temperature increases cause large increases in radiated power.
What is emissivity?
A number between 0 and 1 describing how well a surface radiates compared to a perfect black body. Polished metals have low emissivity; dark rough surfaces have high emissivity.
How hot is the surface of the Sun?
About 5778 K. Using Stefan-Boltzmann with the Sun's radius gives its total luminosity of about 3.8 x 10^26 W.
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