A body which absorbs 100% of the energy that falls on it is known as a blackbody. how much energy will this body emit?
i think it is 100% as well. but i am not sure.
It will emit 100% times the Planck "blackbody function", which varies with wavelength and temperature. The total emitted power per area will be
(sigma)T^4
where sigma is the Stefan-Boltzmann constant
sigma = 5.57*10^-8 W/m^2 K^4
and T is the absolute temperature.
sigma = 5.67*10^-8 W/m^2 K^4
You are close! A blackbody is indeed a theoretical concept that absorbs all incoming electromagnetic radiation across all wavelengths. However, the energy it emits depends on its temperature.
According to Planck's law of blackbody radiation, the energy emitted by a blackbody is directly proportional to its temperature. This relationship is described by the Stefan-Boltzmann law, which states that the total power radiated by a blackbody is proportional to the fourth power of its absolute temperature (in Kelvin).
The formula is:
P = σ * A * T^4
Where:
P is the power radiated (energy per unit time)
σ is the Stefan-Boltzmann constant (approximately 5.67 x 10^-8 W/m^2K^4)
A is the surface area of the blackbody
T is the temperature in Kelvin
So, if a blackbody absorbs all incoming energy, it will emit the same amount of energy. However, the specific energy emitted depends on its temperature, which determines the total power radiated.
Therefore, the answer to your question would be that a blackbody emitting 100% of the absorbed energy would emit an amount of energy proportional to its temperature, as determined by the Stefan-Boltzmann law.