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.

2 answers

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