Quanta Question (1 Viewer)

[the-derivative]

Hey guys,

Got this question from a worksheet, I cant seem to think of what to do.

UV Rays of frequency 8.4 x 10^15 Hz strike a zinc plate ejecting electrons. If all the energy of each photon goes into accelerating one electron, what will the velocity of the electron be?

Thanks in advance guys =)

 

[lolokay]

you know the frequency of the light, so you know the energy per photon (E=hf)
so you know the energy being given to each electron. this energy is going to be equal to the work function for the zinc plate (if youre given it) + the kinetic energy of the electron,
i.e. hf = hf₀ + 1/2 m_ev², and you should know all the other values, so you can rearrange for v

i think this is how you do it at least

edit: ah i assume "all the energy of each photon goes into accelerating .." means you ignore hf₀ then?

 

[study-freak]