0:00
Hi there.
00:01
So for this problem, we are told that light of a wavelength that is given, and that wavelength is equal to a value of 200 nanometers, shines on an aluminum surface, and we are told that 4 .20 electron bolts is required to a jet at an electron.
00:25
So what we are given with that information is the work function.
00:29
So the work function in this.
00:30
Case is 4 .2 electron balls.
00:36
So the question is what is the kinetic energy? so for part a for the fastest of the ejected electrons.
00:45
So to obtain that we know that the kinetic and the maximum kinetic energy of the for the electron is equal to the energy of the photon so that is plams constant times the frequency or also, we can express that as plams constant times the speed of light divided by the wavelength, and this minus the work function.
01:12
And then we can substitute those values in here.
01:17
We know that the product between plams constant and the speed of light, that is a known value of 1 ,240, electron bolts times nanometers, and this divided by the wavelength that is 200 nanometers.
01:31
And this minus the word function that is equal to 4 .20 electron balls.
01:38
So from this we obtain maximum kinetic energy of two electron balls.
01:46
So that's a solution for part a of this problem...