The irradiance for an ideal blackbody is given by the planck for where the symbols have their usual meaning and k represents boltzmann's constant with the value k 1.38x10 jk -8.62x10ev/k use a spreadsheet or some other program to graph this function for 3450k, and 5450k, objects over the wavelength range from10 to 3 μm. plot the radiance in m w/cm2/nm. 4. find a formula that allows you to calculate the wavelength corresponding to the maximunm irradiance for a blackbody. hint: find the condition for a maximum by changing variables according to x he/kt and using your knowledge of calculus. you should end up with an equation that puts conditions on x, e. g. fx) -0. use a numerical method, i. e. newton's method, to find a root of this nonlinear equation. plug the result into r he/akt and voila, you have a formula for the wavelength corresponding to the maximum irradiance for a blackbody. 5. in a 100 w incandescent light bulb the tungsten filament is at 3450k. what is the surface area of the filament?