00:01
Hi there, so for this problem, we need to find the net force that the southern hemisphere of an uniformly charged sphere it serves on the northern hemisphere.
00:14
So we need to spread your answer in terms of the radius capital art and the total charge queue.
00:24
So with that said, we know that from problem 2 .12, the field inside an uniformly charged sphere is the one as from a point charge that we know is 1 over 4 times pythens, epsilon sub 0 times the charge cube divided by the radius of the sphere to the 3.
00:55
And this in the radial direction.
00:59
So the force per unit volume, the force per unit volume is equal to the charge density times the electricity, field.
01:11
So we will have that that is.
01:13
The charge density is the charge divided by the volume that is 1, 4 over 3 times pi times the radius to the 3 because it is the volume of a sphere.
01:25
And this times the electric field that we have is this in here.
01:31
So that is the charge q divided by 4 times pi times epsilon sub 0 times the radius to the 3 in the radial.
01:40
Direction.
01:43
So we can simplify this term as 3 over epsilon sub 0 times the charge capital q divided by 4 times pi times the radius to the 3 and that to the square in the radial direction...