00:01
So on the left here, i have some of the values we'll need to solve this problem.
00:06
I have avagadro's number, the density of copper, the molar mass of copper, the conductivity of copper, the charge of an electron, the mass of an electron, and then the drift velocity that we're given.
00:19
So the first thing you want to do for this problem is find the electron density of copper.
00:24
The electron density is equal to avagadro's number times the density over the molar mass.
00:34
And so in this case, that's equal to about 8 .5 times 10 to the 28 1 over meter cubed.
00:44
So that means there's about 8 .5 times 10 to the 28 electrons in 1 meter cubed of copper.
00:51
So the next step is we want to find the average time interval between successive collisions of electrons, which is tau.
00:59
So we have the equation, conductivity is equal to the electron density times the charge of an electron squared times tau over the mass of an electron...