00:01
Okay, so here we have a photoelectric effect question, and we have photons with a minimum frequency of 3 .2 times 10 to 14 hertz required to emit electrons.
00:11
That's going to be our threshold frequency.
00:13
So we can use the equation hf is equal to phi plus ke max.
00:19
But bear in mind in this scenario, because it's a threshold frequency, the electrons will be emitted with no kinetic energy.
00:25
So we can ignore that for now because ke will be equal to zero.
00:28
This allows us to find our work function.
00:31
So if hf is equal to phi, h is the clank constant, 6 .63 times 10 to the minus 34, and frequency multiplied by 3 .2 times 10 to the 14, and that is equal to phi, which is equal to 2 .12 times 10 to the minus 19 jules.
00:52
Okay then.
00:53
We now have light of wavelength 420 nanometers, and they want us to find the maximum kinetic energy...