What is the Correct Way to Calculate the Work Function of a Material?

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SUMMARY

The correct way to calculate the work function of a material involves using the equation KE = hf - Wo, where KE is the kinetic energy of emitted electrons, h is Planck's constant, and f is the frequency of the incident light. In this discussion, a monochromatic light with a wavelength of 254 nm generates a photocurrent, and a stopping voltage of 2.30 V is required to block this current. The work function (Wo) can be calculated by first converting the stopping voltage to energy units (Joules) and then applying the equations KE = hf - Wo and hf = hc/wavelength. Proper unit conversion is crucial to avoid negative results in the work function calculation.

PREREQUISITES
  • Understanding of the photoelectric effect
  • Familiarity with Planck's constant (h = 6.626 x 10^-34 J·s)
  • Knowledge of energy conversion from voltage to Joules
  • Ability to manipulate equations involving frequency and wavelength
NEXT STEPS
  • Learn about the photoelectric effect and its implications in modern physics
  • Study the conversion of stopping potential to energy units in Joules
  • Explore the relationship between frequency and wavelength in electromagnetic radiation
  • Investigate common errors in work function calculations and how to avoid them
USEFUL FOR

Students studying physics, particularly those focusing on quantum mechanics and the photoelectric effect, as well as educators looking for practical examples of work function calculations.

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Homework Statement



When a monochromatic light with a wavelength of 254 nm falls onto the surface of a particular metal it causes a photocurrent to flow. A stopping voltage of 2.30 V is required to completely block the photocurrent. What is the work function of the material?

Homework Equations


KE = hf - Wo
hf = hc/wavelength


The Attempt at a Solution


I keep getting a negative number which is an impossible answer for a work function.
Any help would be greatly appreciated.

Thank you.
 
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Before solving convert stopping potential to energy units.(J)
Show your calculations.
 
Thanks for pointing that out. I had the wrong units which messed up everything.
 

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