A large cavity that has a very small hole and is maintained at a temperature T is a good approximation to an ideal radiator or blackbody. Radiation can pass into or out of the cavity only through the hole. The cavity is a perfect absorber, since any radiation incident on the hole becomes trapped inside the cavity. Such a cavity at 500.C has a hole with area 6.00 mm2. How long does it take for the cavity to radiate 300 J of energy through the hole?

The intensity of blackbody radiation peaks at a wavelength of 583 nm. (a) What is the temperature (in K) of the radiation source? (Give your answer to at least 3 significant figures.) K (b) Determine the power radiated per unit area (in W/m2) of the radiation source at this temperature. W/m?

A square metal plate with a side 0.4m is heated to a temperature of 2000k by passing a current through it. Assuming that it behaves like a blackbody, how much power does the plate radiate under these conditions?

Please help! A student in a lecture hall has 0.310 m^2 of skin (arms, hands, and head) exposed. The skin is at 34.0°C and has an emissivity of 0.970. The temperature of the room is 20.2°C (air, walls, ceiling, and floor all at the same temperature). The Stefan-Boltzmann constant is 5.670 x 10-8 w/ (m2. k4 ). a) at what rate does the skin emit thermal radiation? b) at what rate does the skin absorb thermal radiation? THANK U