Name __Taylor Bushart______ Blackbody Radiation
Go to http://phet.colorado.edu/simulations/sims.php?sim=Blackbody_Spectrum and click on Run Now.

1) In this lab, you will use the Blackbody Spectrum Simulation to investigate how the spectrum of electromagnetic radiation emitted by objects is affected by the object's temperature. In this simulation, you can input the temperature and observe the spectrum of the radiation emitted.
a) The temperature of stars in the universe varies with the type of star and the age of the star among other things. By looking at the shape of the spectrum of light emitted by a star, we can tell something about its average surface temperature.
i) If we observe a star's spectrum and find that the peak power occurs at the border between red and infrared light, what is the approximate surface temperature of the star? (in degrees C)
When the temperature is 4040 Kelvin the power is right between red and infrared.
3767 C

ii) If we observe a stars spectrum and find that the peak power occurs at the border between blue and ultraviolet light, what is the surface temperature of the star? (in degrees C) When the temperature is 7100 Kelvin the power is right between blue and ultraviolet. 6827 C

b) Light bulbs operate at 2500 degrees C.
i) What is the wavelength at which the most power is emitted for a light bulb operating at 2500 C? 2500 C + 273.15 = 2773 Kelvin
The power is at 1050 (nanometers).

ii) Explain why regular incandescent bulbs waste a lot of energy. Be sure to include your reasoning.
The light emitted has wavelengths that are longer than the visible. The power used to produce light that is not at visible is wasted. Because only a small percentage of the energy goes into producing visible light, regular incandescent bulbs are inefficient.

c) Use the Spectrum