How Does the Photoelectric Effect Determine Electron Speed?

Click For Summary

Homework Help Overview

The discussion revolves around the photoelectric effect, specifically examining how the energy of incident light affects the speed of an ejected electron. The original poster presents a scenario involving a metal target, a specific wavelength of light, and the work function required to eject an electron.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to calculate the speed of an electron using kinetic energy equations and expresses uncertainty about the formulas being applied. Some participants confirm the arithmetic and the use of formulas, while others question the appropriateness of the methods used.

Discussion Status

The discussion is ongoing, with some participants providing supportive feedback on the calculations. There is a general agreement on the correctness of the mathematics, but questions remain regarding the formulas and their application.

Contextual Notes

Participants are navigating the complexities of the photoelectric effect and the associated calculations, with some uncertainty about the formulas and their relevance to the problem at hand.

sadakaa
Messages
18
Reaction score
0
1. Light of a wavelength 410nm is incident on a metal target and an electron is eject from the surface. The work required to remove this electron from the metal is 3.0 x 10^-19 J. The elctron then travels straight to a collection plate. The different in electric potential between the collector and emitter (target) is .5V (the emitter is at higher potential).

What is the speed of the electron the instant before it strikes the collector

I found that using KEmax = hf - W0, KEmax = 1.848 x 10^-19 J



2. d KE = -|qe Vthreshold |= -|(-1.6x10^-19C)(.5V)|= -8.0 x 10^-20 J



3. v = ROOT (2KE/m) = 419313.94 m/s

i'm not sure if i should be using this formula, nor am I sure how I could apply the kinematics forumlas. Let me know
 
Physics news on Phys.org
Welcome to the forums,

Assuming you have done the arithmetic correctly, your answer should be good. It looks to be the right order of magnitude to me :approve:
 
the mathematics are correct, I'm just not sure if I'm using the correct forumlas
 
You're working with the correct formula.
 

Similar threads

Undergrad Photoelectric effect and Saturation Current
  • · Replies 12 ·
Replies
12
Views
2K
In photoelectric effect, why does photon prefer K shell electron?
  • · Replies 1 ·
Replies
1
Views
4K
Photoelectric effect calculation
  • · Replies 8 ·
Replies
8
Views
3K
Photoelectric Effect Graph and Work Function Questions
  • · Replies 25 ·
Replies
25
Views
5K
Graduate Saturation voltage for photoelectric current
  • · Replies 16 ·
Replies
16
Views
3K
Another Photoelectric effect problem
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Ejection of Only one electron by a Photon in the Photoelectric effect
  • · Replies 5 ·
Replies
5
Views
3K
How to Calculate the Maximum Energy of Ejected Electrons?
  • · Replies 5 ·
Replies
5
Views
3K
High School Photoelectric effect and atomic excitation
  • · Replies 3 ·
Replies
3
Views
3K
How Do You Calculate Photoelectron Emission from Sodium Surfaces?
  • · Replies 1 ·
Replies
1
Views
3K