# Stefan's Law

## Key Questions

5.670367 × 10^-8 kg s^-3 K^-4

#### Explanation:

Stefan Boltzmann constant is usually denoted by $\sigma$ and is the constant of proportionality in Stefan Boltzmann's law.

Here, $k$ is the Boltzmann constant, $h$ is Planck's constant, and $c$ is the speed of light in a vacuum.

Hope this helps :)

• The Stefan-Boltzmann law is $L = A \sigma {T}^{4}$, where:

• $A$ = surface area (${m}^{2}$)
• $\sigma$ = Stefan-Boltzmann (~5.67*10^-8Wm^-2K^-4)
• $T$ = surface temperature ($K$)

Assuming the object acts as a black-body radiator (an object that emits energy from the entire EM spectrum), we can find the rate of energy emission (luminosity) given the objects surface area and surface temperature.

If the object is a sphere (like a star), we can use $L = 4 \pi {r}^{2} \sigma {T}^{4}$

For a given object with a constant surface area, the Stefan-Boltzmann law says that luminosity is proportional to the temperature raised to the fourth power.

• The Stefan-Boltzmann law is $L = A \sigma {T}^{4}$, where:

• $A$ = surface area (${m}^{2}$)
• $\sigma$ = Stefan-Boltzmann (~5.67*10^-8Wm^-2K^-4)
• $T$ = surface temperature ($K$)

This law is used to find the luminosity (the rate of energy released), for an object given its surface temperature. This law assumes the body acts as a black-body radiator (an object that emits energy from the entire EM spectrum)

For a given object with a constant surface area, the Stefan-Boltzmann law says that luminosity is proportional to the temperature raised to the fourth power.