00:01
So for this first part, we're relatively close to this sheet, and we remember that whenever we have a very, very large sheet, an infinite sheet, that the electric field is simply the surface charge area density divided by 2, epsilon naught.
00:21
Epsilon is simply a constant, 8 .85 times 10 to the minus 12.
00:31
And if we explicitly write what sigma is, the surface charge, area density, whenever we have a square like this, the area density is just a, or l squared.
00:51
So a is just the length of that guy squared.
00:54
It's dimensions divided by 2 epsilon or not.
01:01
Plugging this in, we get 6 .62 times 10.
01:09
To the 2 newton for kuwam or 662 newton for kuwam so this guy's not too bad you just plug it in a is l squared now what happens if we get a little further away so for part b we're a bit further away well if you get really really far away it's almost like this sheet becomes a point charge and we know that the electric field due to a point charge e equals k which is a constant q which is the charge associated with that object divided by r squared well we know q we know k and r is simply the distance away so plugging it in k is simply a constant 99 9 times into the 9 q is given and all that we must do is plug in our distance, which is the radius that we are away from this object...