please complete the following questions.

Lab 9.Thermal Radiation andBlackbodySpectrum

Introduction

In thisexperiment, you willuse theBlackbody Spectrum Simulationto 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.

Objectives

Explore the blackbody spectrumValidate the Wien'sDisplacement LawValidate the Stefan-Boltzmann Law

Theory

Thermal radiation is the emission ofelectromagnetic wavesfrom all matter that has atemperaturegreater thanabsolute zero. Thermal radiation reflects the conversion ofthermal energyintoelectromagnetic energy. Thermal energy is the kinetic energy of random movements ofatomsandmoleculesin matter. The radiation is not monochromatic, i.e., it does not consist of only a single frequency, but comprises a continuous spectrum of photon energies, its characteristic spectrum. If the radiating body and its surface are inthermodynamic equilibriumand the surface has perfect absorptivity at all wavelengths, it is characterized as ablack body. A black body is also a perfect emitter. The radiation of such perfect emitters is calledblack-body radiation.The total energyPper unit of time per unit of surface areaAradiated by a black body maintained at a temperatureT, and is known as theStefan-Boltzmann law:

P=AT⁴(1)

whereis theStefan-Boltzmann constant,5.6710⁸Wm²K⁴.To remain in thermal equilibrium at constant temperatureT, the black body must absorb or internally generate this amount ofpowerPover the given areaA.Wien's displacement lawstates that theblack-body radiationcurve for different temperatures will peak atdifferentwavelengthsLthat are inversely proportional to the temperature

L=b/T(2)

,whereTis the absolute temperature,bis aconstant of proportionalitycalledWien's displacement constant, equal to2.897771955...103m*K,orb 2898 m*K. This is an inverse relationship between wavelength and temperature. So the higher the temperature, the shorter or smaller the wavelength of the thermal radiation. The lower the temperature, the longer or larger the wavelength of the thermal radiation. For visible radiation, hot objects emit bluer light than cool objects.

Apparatus

List the equipment or objects used in this lab.

Procedure

1)Start the simulationhttps://phet.colorado.edu/sims/html/blackbody-spectrum/latest/blackbody-spectrum_en.html

2)Check the boxes Graph ValuesandLabels3)Change the temperature from Earth to Sirius and record the TemperatureT,maximum wavelengthL(the yellow number under the wavelength axis),and spectral power densityP(the yellow number on the left from the Spectral Power Density axis)in the Data Table.4)Calculate the values ofX1andX2as it displayed in the Data Table .5)Plot the Graph 1.showingLasafunction ofX16)Plot the Graph 2 showingPasafunctionofX2.

DataTable.

Body	T,K	X1=1/T,K-1	X2=T4,K4	L,m	P,MW/m2/m
Earth
Light Bulb
Sun
Sirius A

Analysis

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 tellsomethingabout its average surface temperature.

1.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 degreesK)2.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 degreesK)

Conclusion

Did you prove the Wien's and Stefan Boltzmann Laws?Why?