physical代写 Simulation Lab代写

Photoelectric Effect Simulation Lab Due Monday, April 4, 2018

Names:____________________________________________________

physical代写 To be able to explain how the photoelectric effect experiment works and why a photon model of light is necessary to explain the results.

Learning Goal: physical代写

To be able to explain how the photoelectric effect experiment works and why a photon model of light is necessary to explain the results.physical代写

To answer the following questions, use simulationhttp://phet.colorado.edu/en/simulation/photoelectric (Phet).physical代写

1.Suppose you set up the experiment so that the plate is ejecting electrons. Predict which of the following changes to the experiment could increase the maximum initial kinetic energy of the ejected electrons. (Select all that apply) Then test your prediction.physical代写

A. Increasing the intensity of the light beam                                                                            B. Decreasing the intensity of the light beam

C. Increasing the wavelength of light                                                                                         D. Decreasing the wavelength of light

E. Increasing the frequency of light                                                                                            F. Decreasing the frequency of light

G. Increasing the voltage of the battery                                                                                     H. Decreasing the voltage of the battery

I. Replacing the target with a material that has a larger work function                              J. Replacing the target with a material that has a smaller work function

2.Suppose now you set up the experiment so that the light intensity is non-zero but the plate is NOT ejecting electrons. Predict which of the following changes to the experiment could make the plate start ejecting electrons? (Select all that apply) Then test your prediction.physical代写

A. Increasing the intensity of the light beam                                                                           B. Decreasing the intensity of the light beam

C. Increasing the wavelength of light                                                                                        D. Decreasing the wavelength of light

E. Increasing the frequency of light                                                                                           F. Decreasing the frequency of light

G. Increasing the voltage of the battery                                                                                    H. Decreasing the voltage of the battery

I. Replacing the target with a material that has a larger work function                             J. Replacing the target with a material that has a smaller work function

3.What causes the electrons to be ejected from the left plate in this simulation?physical代写

A. The force exerted on the electrons by the battery                                                                          B. The beam of light shining on the plate

C. Both A and B.                                                                                                                                         D. Neither A nor B.

4.(Free Response) This section is designed to help you understand how the observations from the photoelectric effect experiment lead to and make sense only with a photon model of light. The following are key experiments from the photoelectric effect. For each, explain   physical代写

• what you observe
• what conclusions you can draw about light and why, and
• how it is or is not consistent with what you would expect to observe if light matched the classical wave model and with what you would expect to observe if it matched the photon model of light.

a. Light is shining on a metal and electrons are being emitted. You turn the intensity down very, very low.

b. Light is shining on a metal plate and electrons are being emitted. Without changing the intensity, you make the wavelength longer and longer.

5.If you have the experiment set up so that electrons are being emitted from the metal plate, which of the following are true or false?physical代写

• As long as conditions do not change, all emitted electrons have the same initial kinetic energy. T/F
• The work function for the metal is different for different electrons. T/F
• The energy of the photons hitting the plate must be less than the work function of the metal. T/F
• The electrons emitted with the largest initial kinetic energy are those that were the least tightly bound in the metal. T/F

Let’s study Sodium:  physical代写

6. For what wavelength range do you see emission of electrons from the sodium target?physical代写

7. For what wavelength range do you see no emission of electrons from the sodium target?

8. When you create electrons from the sodium target with light with a wavelength of 500nm, what is the stopping potential in that case?physical代写

9. What is the energy of these electrons emitted from sodium in eV?

10. What is the energy of these electrons emitted from sodium in J?physical代写

11. What is the stopping potential for UV light with a wavelength of 350nm? (At what voltage do electrons stop flowing? Express this as a positive number.)

12. Draw a graph showing how the current in the wire depends on the light intensity for radiation of the sodium target with light with a wavelength of 350nm. Plot the current as a function of % intensity.physical代写

13. Draw the current as a function of the battery voltage for a radiating wavelength of 350nm. b. Draw how the kinetic electron energy depends on the frequency of the light.

14.  How does the energy of the electrons depend on the intensity of the light? And a bit of analysisphysical代写

15. Determine the work function of sodium in eV and in Joule?

16. Why does the photoelectric effect suggest that light acts like a particle?physical代写

18. Explain what the phrase – ‘the work function for sodium’ – means in a way that would make sense to a non-science person. (Be very specific.)

19. In the photoelectric effect experiment, the graph of current vs battery voltage for a metal with light of a particular frequency shining on it looks like the curve below. This graph represents current vs voltagefor 200nm light shining onto Cadmium (Cd) which has a work function of 4.07 eV.physical代写

• Explain your reasoning for whythis curve has the shape that it does. In your answer, you should address: Why is current level at V>0, why does current go to zero at some negative voltage and what determines that voltage, and why does current start decreasing steadily at V<0?

• What is the stopping potential in this situation (in eV)? (Remember stopping voltage is expressed as a positive number).physical代写

更多其他：Blogs Login 文学论文代写 Report代写 ORDER NOW Admission Essay代写 艾莎代写 Review代写 研究论文代写 Case study代写 Proposal代写 Academic代写 Home Top Writers

合作平台：天才代写 幽灵代写  写手招聘