A blackbody (a hollow sphere whose inside is black) emits radiation when it is heated. The emittance (, W/m3), which is the power per unit area per wavelength, at a given temperature (, K) and wavelength (, m) is given by the Planckdistribution,

=225(1/1)

where is Planck's constant, is the speed of light, and is Boltzmann'sconstant.

Determine the temperature in degrees Celsius at which a blackbody will emit light of wavelength 2.19m with an of5.171010W/m3.

The power per unit area emitted can be determined by integratingbetween two wavelengths,1and2.However, for narrow wavelength ranges(),the power emitted can be simply calculated as the product ofand.

power emitted=

Using the conditions from the first part of the question, determine the power emitted per square meter (W/m2) between the wavelengths 2.18m and2.20m.