00:01
Hi there! so we are cutting the drift velocity of an electron in a copper wire that has a radius that is equal to 900 millimeters.
00:17
That means we can have this into meters because we know that meter is equal to 1 ,000 millimeters.
00:29
So from this will obtain 0 .9 meters.
00:37
Now with that said, we are also given that it carries a current, an uniform current, i, that is equal to 17 miliamper.
00:51
That means 17 times 10 to the minus 3 ampers.
00:57
Now, with that set, we need to calculate the drift velocity.
01:04
Now to calculate the drift velocity we use the following equation that is the current divided by the number of electrons per unit volume that we are going to call you simply and this times the conceptual area and this times the charge of an electron.
01:34
The cross -ceptional area is just pi times the radius square.
01:41
And to calculate the number of electrons per unit length per volume, per unit volume, that is defined as the density, in this case of the material, which is cooper in this case times the apocratus number, and this divided by the molar mass.
02:05
Now, in the case of cooper, we know that the density of cooper is approximately a value of 9 times 10 to the 3 kilograms per cubic meter, and this times the abogratus number.
02:26
We know that the apogratus number is equal to 6 .02 times 10 to the 23 mole to the minus 1.
02:42
And this divided by the molar mass of cooper, which we know is 63 .0 .60 .6 .63 .5...