2. 1. What is the mass of a photon? 2. Does a photon have momentum? 3. Using your Compton notesheet, find an equation that uses momentum.

3. Mr. Davis Baltimore Poly

4. What equation did you learn last year for momentum? P=mv Momentum = Mass*Velocity

5. What is Einstein’s Famous Equation? E= mc 2

6. For a particle with zero momentum p = 0: A light photon has m = 0, but it does have momentum p: E = mc 2 E = pc

7.  What is one way Light, or Photons, act as a wave?  Interference  Reflection  Dispersion

8.  What is one way Light, or Photons, act as a particle?  Compton Effect  Photoelectric Effect

9. Louis de Broglie hypothesized that because photons have wave properties, all matter could have wave properties. He was the first person to win a Nobel Prize in Physics for something that he did in his doctoral dissertation.

10. What is a property that all waves have? Wavelength!!! If Matter acts like a wave, it should have a _________?

11. Lets find the wavelength of a photon. Using the equations from the Do Now, Solve for the wavelength in terms of momentum De Broglie Wavelength of a photon:

12. All objects have wavelengths which can be found from their momentum Substitute in what we know about momentum of objects with mass to the previous de Broglie equation! de Broglie Wavelength:

13. Calculate the de Broglie wavelength for an electron moving at 10 7 m/s. Mass of an electron: 9.1x10 -31 kg 7.28x10 -11 m

14. That’s all there is to de Broglie. Tuesday we will have a 20 minute “mini-quiz” It’s short!! It will be on a half sheet of paper

15.  You have the rest of class to work on your classwork.  You will have an exit ticket at the end of class.  Use SI units (kg, m, ect)

16.  If Mr. Davis runs at 4.38 m/s and is 60kg. What is his de Broglie wavelength?  Bonus: ◦ How many minutes does it take him to finish a half marathon, 21km. ◦ How fast per mile does Mr. Davis run if a mile is 1600m. (For example 8:10 minutes per mile)

17.  Calculate the de Broglie wavelength for a 50 g ball thrown with a speed of 25 m/s.

18.  The de Broglie wavelength of an object depends on what two variables?  Mass  Velocity

19.  Which of the following has the longest de Broglie wavelength if they were moving at the same speed? ◦ A marble ◦ A Baseball ◦ A Car ◦ The Earth

20.  Calculate the de Broglie wavelength of a.5kg basketball sitting stationary on the ground. It’s undefined, because the object is stationary.

21.  You have the rest of class to work on your classwork “de Broglie Wavelength”.  There is a bonus classwork if you finish early.  You will have an exit ticket at the end of class.

22.  Design and solve your own de Broglie wavelength problem!  Your problem should be at least two sentences and make your problem involve stuff you can touch and see.  Bonus points for creative problems!!!