A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 2 years ago
Light with a wavelength of 5.0 · 107 m strikes a surface that requires 2.0 ev to eject an electron. Calculate the energy, in joules, of one incident photon at this frequency.
anonymous
 2 years ago
Light with a wavelength of 5.0 · 107 m strikes a surface that requires 2.0 ev to eject an electron. Calculate the energy, in joules, of one incident photon at this frequency.

This Question is Closed

theEric
 2 years ago
Best ResponseYou've already chosen the best response.1Hi! Knowing wavelength (through air, I assume), you can find out the energy of the photons! The energy of a photon is always \(E=hf\). There, \(h\) is Planck's constant and \(f\) is the frequency. Many people use \(v\) for the frequency, too, as you'll see on Wikipedia. The frequency and wavelength are related by the speed. For a photon, the speed is the speed of light. In air, it's about \(3\times10^8\ \rm m\). We'll say that that speed is \(c\). _________________________________________________________ I'm going to show you how to relate these two, even though you only need the end result. Learn this if you can! It's handy to understand. Then we can use the velocity equation, where \(v\) is for velocity, and say \(v=\dfrac{\Delta d}{\Delta t}\)dw:1398209004730:dwSo distance is wavelength. The time per cycle (1 wavelength) is the reciprocal of the wavelengths per time. The cycles (wavelengths traversed) per time is the frequency. The reciprocal of the cycles per time is the reciprocal of frequency. Now, the displacement \(\Delta d\) is wavelength \(\lambda\). And the time per that displacement \(\Delta t\) is the reciprocal of frequency, so \(\dfrac1f\). Substituting, \(v=\dfrac{\Delta d}{\Delta t}=\dfrac{~~~\lambda~~}{\frac1f}=\lambda f=c\) ___________________________________________ Now \(c=\lambda f\implies f=\dfrac c\lambda\) Substituting that into what we had for energy, \(E=hf=h\dfrac c\lambda\) So, you can remember all that, or the \(c=\lambda f\), or the \(E=h\dfrac c\lambda\).

theEric
 2 years ago
Best ResponseYou've already chosen the best response.1Do you have any questions?

anonymous
 2 years ago
Best ResponseYou've already chosen the best response.0No i think that should do it. I never even know what formulas to use so now that I do that should be good enough.

theEric
 2 years ago
Best ResponseYou've already chosen the best response.1Haha, okay! If not, feel free to let me know.
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.