 So now that you've answered the conceptual questions about point charges on the backside of the sheet, it's time to move on to our calculation question. So I've given you one of these here. We'll get more practice on the homework and in recitation. But we're trying to find the electric field at a particular distance from a particular point charge. So in this case, when I move over to my little workspace here, I'm not going to use the generic equation, which relates the electric field to the force, but the specific equation for the electric field for a point charge. And you can go back and look at the videos on the point charge electric fields to understand this a little better. But it's got k, which is Coulomb's constant, the charge and the distance squared. And it's only a single charge we're using here, so it's not q1 and q2. When I look at the values I have for this particular problem, my k is my standard constant, 8.99 e to the ninth, and that's Newton meter squared per Coulomb squared. My charge was 3.60, notice e to the minus sixth Coulomb, because it was a micro Coulomb. And my distance was 0.250 meters, and don't forget to square it. I'll let you plug this in for the actual calculation in your calculator, but let me work through the units with you here. See, the Coulomb on top cancels one of the Coulomb's on the bottom here, but leaves one. My meter squared cancels my meter squared there. So again, our expected unit for the electric field and the listed value for the electric field on the back or on the front side of your equation sheet is always Newtons per Coulomb. So you'll need to figure out the actual value, but don't forget your units when you do that calculation. Now to give you a hint, you should have a fairly large electric field here, but not too huge, something like 100,000 as opposed to the backside of the sheet, but it will definitely be less than a million Newtons per Coulomb. So you're going to have something in that range. Go ahead and do that calculation. Show your work and make sure that you're ready to turn your worksheet in.