Calculate Electron Kinetic Energy: Photon Frequency & Negative Potassium Plate

  • Thread starter Thread starter Aran
  • Start date Start date
  • Tags Tags
    Physics
AI Thread Summary
A photon with a frequency of 5.8 × 10^14 Hz impacts a negatively charged potassium plate, which has a work function of 3.6 × 10^-19 J. To find the kinetic energy of the ejected electron, the energy of the photon must be calculated using the equation E = hf, where h is Planck's constant. The calculated energy of the photon exceeds the work function, allowing for the determination of the kinetic energy. The final calculated kinetic energy of the electron is 2.454 × 10^-20 J, which is consistent with the expected results. Understanding these concepts is crucial for solving similar physics problems.
Aran
Messages
2
Reaction score
0
A photon with a frequency of 5.8 × 1014 Hz strikes a clean, negatively charged potassium plate. The work function of potassium is 3.6 × 10-19 J. Calculate the kinetic energy of an electron ejected from the plate by this electron.

Explanation is here i think:

bbc.co.uk/scotland/education/bitesize/higher/physics/radiation/optoelectronics1_rev.shtml

I don't understand anything in physics and I have this home test, and this is the only question I need answered. If you can please help me, I would greatly appreciate it. Thank you ^^
 
Physics news on Phys.org
What have you done yourself? That page is very clear and basically gives you all the tools you need to answer the question.
 
I got 2.454x10^-20 J as my final answer
 
Looks ok to me.
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top