Solve Photoelectric Effect: Find Work Function & Planck's Constant

  • Thread starter Thread starter patapat
  • Start date Start date
AI Thread Summary
To solve the photoelectric effect problem, the work function of potassium and Planck's constant need to be determined using given wavelengths and stopping potentials. The relevant equation is eV₀ = hf - φ, where φ is the work function. The stopping potentials for 450 nm and 300 nm light are 0.52 V and 1.90 V, respectively, indicating that the work function remains constant across both scenarios. By setting up two equations based on the stopping potentials and solving for Planck's constant first, the work function can then be calculated. This method effectively utilizes the relationship between energy, frequency, and the work function.
patapat
Messages
20
Reaction score
0

Homework Statement


When light of wavelength 450 nm is shone on potassium, photoelectrons with stopping potential of 0.52 V are emitted. If the wavelength of the incident light is changed to 300 nm, the stopping potential is 1.90 V. Using only these numbers together with the values of the speed of light and the electron charge, do the following.
(a) Find the work function of potassium
(b) Compute a value for Planck's constant.

Homework Equations


eV_{0}=hf-\phi


The Attempt at a Solution


I'm not sure how to do this problem. Since they ask us to compute a value for Planck's constant I am not sure that we actually use the equation stated above. I assume that the work function is the same for both cases of wavelength and stopping potential, but I'm not sure what the relationship is.
Thanks in advance for the help.

-pat
 
Physics news on Phys.org
it should be V_0 not V^0, thanks.
 
You can start with (b) and then do (a). Have two equations of (phi) = hf - eV_o, and set them equal to each other since they each the same phi value. You should then be able to solve for h. Then plug h into one of the equations to find phi
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Struggling to make relation between elastic force and height'
Hello guys this is what I tried so far. I used the UTS to calculate the force it needs when the rope tears. My idea was to make a relationship/ function that would give me the force depending on height. Yeah i couldnt find a way to solve it. I also thought about how I could use hooks law (how it was given to me in my script) with the thought of instead of having two part of a rope id have one singular rope from the middle to the top where I could find the difference in height. But the...

Similar threads

Back
Top