- #1
ghostbuster25
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HELP! photoelectric effect
Ok guys got a question on quantum physics - photoelectric effect i want to run past you before i attempt a solution.
The question is as follows;
In a photoelectric-effect experiment, light of wavelength 420nm is incident on a sample of sodium. The work function of sodium is 3.67*10-19 J.
Calculate the stopping potential required to stop all electrons from reaching the anode.
Ok so I am planig to use einsteins photoelectric equation of 1/2 mev2 = hf-psi(as in work function)
Im guessing i need to convert the wavelength to frequency so have come up with the solution 7.137915667e11
so this in the equation gives me 6.63*10-34 * 7.14285713*1014 - 3.67*10-19 J = n = -3.665267562
So this is the result of the maximum kinetic energy E of the electrons.
I am a bit worried as my result is a minus! which i imagine is impossible
after that i believe i am to work out the potential differnence to stop the electrons.
That i am a bit unclear on how to do so any help would be much appreiciated :)
Ok guys got a question on quantum physics - photoelectric effect i want to run past you before i attempt a solution.
The question is as follows;
In a photoelectric-effect experiment, light of wavelength 420nm is incident on a sample of sodium. The work function of sodium is 3.67*10-19 J.
Calculate the stopping potential required to stop all electrons from reaching the anode.
Ok so I am planig to use einsteins photoelectric equation of 1/2 mev2 = hf-psi(as in work function)
Im guessing i need to convert the wavelength to frequency so have come up with the solution 7.137915667e11
so this in the equation gives me 6.63*10-34 * 7.14285713*1014 - 3.67*10-19 J = n = -3.665267562
So this is the result of the maximum kinetic energy E of the electrons.
I am a bit worried as my result is a minus! which i imagine is impossible
after that i believe i am to work out the potential differnence to stop the electrons.
That i am a bit unclear on how to do so any help would be much appreiciated :)