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Post-Assessment #31

Posted: Fri Apr 20, 2018 12:49 pm
by Alysia Garcia 1B
If 3.607 x 10-19 J is required to remove an electron with zero kinetic energy from a metal surface, what would be the longest wavelength light that could do this?
I understand that you have to use Ek= Energy of incoming photon - work function, but what would I use for the kinetic energy?

Re: Post-Assessment #31

Posted: Fri Apr 20, 2018 1:34 pm
by NabilaNizam-1K
If you are calculating the kinetic energy of the ejected electron, you can use the equation
where m=mass of an electron and v=velocity of the electron after it's ejected

Re: Post-Assessment #31  [ENDORSED]

Posted: Sat Apr 21, 2018 3:54 pm
by Sam Metzger 1C
For this problem, the kinetic energy is zero so the energy of the photon would equal the work energy. From here, we can find the wavelength by using the equations E=hv and c=v(wavelength) and solve for the wavelength.