Two point charges q_1 = +2.40 nC and q_2 = -6.50 nC are 0.100 m apart. Point A is midway between them; point B is 0.080 m from q_1 and 0.060 m from q_2 (Fig. E23.19). Take the electric potential to be zero at infinity. Find (b) the potential at point B.

Video transcript

Hey everyone in this problem. We have an experimental setup consisting of two charged particles. K. Is positive. 1.2 micro columns. L. Is negative. 3.6 micro columns. Their separation is 29 centimeters. Okay we're gonna assume the electric potential is zero at infinity. And we are asked to determine the electric potential at a 00.20 centimeters from K. And 21 centimeters from L. Let's just draw a quick little diagram. So we have this point K. Here And this is a charged particle with charge 1.2 micro collapse. We have a point L. Again a charged particle negative 3. micro columns. These are 29 centimeters apart. Okay. And we want to determine the electric potential at a point that is 20 centimeters from K. And 21 centimeters from L. Okay so we can imagine this point here of interest With a distance of 20 cm. Okay. In a distance of 21 cm to L. A. And this is the point where we want to find the voltage or sorry not the voltage. Yeah, the electric potential. Okay let's get started. So we know that we can write the electric potential V. 1/4 pi you're not many times the sum. In this case we have two charged particles. So are some is going to go from 1 to 2 Q. I over our eye. Okay. Alright. So 1/4 Pi N not this is going to be 9.0. Okay, this is a standard value. Look it up in a textbook or in a table that your professor provided? Newton meter squared whoops. Not cute meter squared per time squared. And then we have this some Okay, now the first thing in the summer we're gonna have Q one. Okay so let's call. Kay our first particle. Okay so Q one the charge of that particle 1.2. We have micro columns. So we're gonna have times 10 to the negative six columns. Okay. We want to enter standard unit. So everything matches divided by r the distance to the point of interest. This is 20 centimeters. Okay so 0.2 m. Okay? And then we have to add same thing but for the other Particle. Oh Okay. So we're gonna get negative 3.6 Times 10 to the -6. Cool. Divided by and then this time are is going to be 0.21 m. Okay. That distance from the point of interest. All right now we can work this out. We get 9.0 times 10 to the exponent nine Newton meter squared per Coolum squared times. This is going to give us negative 1.1143 times 10 to the negative five columns per meter. And we're gonna get one. Cool. Um canceling one m, canceling, We get negative 100287. And this is going to be newton meter per Cool. Oh well this is just newton meter is a jewel. Okay, so a jewel per kula which is equal to voltage V. Alright, putting this into kilowatts, Like the potential solutions we get - kilovolts. Okay, and so our answer, The electric potential at this point is going to be D - kilovolts. That's it for this one. Thanks everyone for watching. See you in the next video.