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Chapter 1, problem 33

Posted: Sat Jul 08, 2017 1:07 am
by Stephanie H
The velocity of an electron that is emitted from a metallic surface by a photon is 3.6*10^3 km/s.
a) What is the wavelength of the ejected electron?
b) No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 2.50* 10^16 Hz. How much energy is required to remove the electron from the metal surface?
c) What is the wavelength of the radiation that caused the photoejection of the electron?
d) What kind of electromagnetic radiation was used?

Did anyone get 1.07*10^-17 J for part b? This is what I did to get my answer: (0.5*9.109*10^-31*(3.6*10^6)^2=(6.626*10^-34)(2.50*10^16)-work function

Re: Chapter 1, problem 33

Posted: Sat Jul 08, 2017 10:13 am
by Ricky Z1D
This was one of the problems done during the Wednesday review session. The answer was 1.66 x 10-17 J. The numbers you multiplied by were exactly what we used, so may be we just rounded it differently.

Re: Chapter 1, problem 33

Posted: Sat Jul 08, 2017 12:54 pm
by Stephanie H
I figured out how you guys got 1.66* 10^-17, (0.5*9.109*10^-31)(3.6*10^3)^2=(6.626*10^-34)(2.50*10^16)-workfunction.

I used (3.6*10^3*10^3) to convert the speed from km/s to m/s, and the equation above just keeps the km/s unit.