Photoelectric Effect: Solving a Stopping Potential Problem

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SUMMARY

The discussion centers on a problem related to the photoelectric effect from University Physics 13th Edition, specifically calculating the work function using stopping potential and frequency of light. The user calculated a work function of 5.17 eV using the formula hf = work function, with h = 6.626x10^-34 and e = 1.602x10^-19. However, the textbook states the work function as 4.8 eV. The community member suggests that the user is likely trying to find the work function for a specific metal and points out a potential error in unit conversion, indicating that the right-hand side of the equation should be in joules (J) rather than volts (V).

PREREQUISITES
  • Understanding of the photoelectric effect and its equations
  • Familiarity with Planck's constant (h = 6.626x10^-34 J·s)
  • Knowledge of electron charge (e = 1.602x10^-19 C)
  • Basic skills in unit conversion between joules and electron volts (eV)
NEXT STEPS
  • Review the concept of stopping potential in the context of the photoelectric effect
  • Learn about the significance of the work function in different metals
  • Study unit conversion techniques between joules and electron volts
  • Explore additional problems in University Physics 13th Edition related to the photoelectric effect
USEFUL FOR

Students studying physics, particularly those focusing on the photoelectric effect, as well as educators and anyone seeking to deepen their understanding of quantum mechanics and energy conversion in physics.

nichelfish
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Hey guys, thanks for any help in advance. I'm working through some exercises in University Physics 13th Edition and have an issue with a photoelectric effect question.

I'm given a graph that represents stopping potential as a function of frequency of light falling onto the surface (attached is a drawing, didn't want to post a direct pic incase it went against the rules). At a stopping potential of 0, the frequency is 1.25x10^15 Hz. As in this case hf=work function (and using h=6.626x10^-34 and e as 1.602x10^-19) I get, using parenthesis to try and make it clearer:

(1.25x10^15)x(6.626x10^-34) = 8.2825x10^-19 V

Converting to eV
(8.2825x10^-19) / (1.602x10^-19) = 5.17 eV.

The answer listed in the textbook gives 4.8eV. I've tried calculations for other points along the line (larger frequencies and stopping potentials) and get the same answer.

Anybody able to hint at as to where I may be going wrong?

Thanks in advance for any help.
 

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Welcome to PF. Could you tell me what are you trying to find in particular? I'm guessing you're trying to find the work function for the particular metal. If that's the case, I don't see any error on your part.
 
Other than your 1st eq. rt-hand-side should be J, not V, I see no error either.
 

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