## anonymous 4 years ago Identical point charges Q are placed at each of the four corners of a rectangle measuring 2.03 m by 3.39 m. If Q = 34.9 μC, what is the magnitude of the electrostatic force on any one of the charges?

1. JamesJ

You here?

2. anonymous

I am, working between my HW site and here

3. JamesJ

4. JamesJ

Now, write $$F_{12}$$ for the force of charge $$Q_2$$ on $$Q_1$$. By Coulomb's law it is $F_{12} = \frac{Q_1Q_2}{4 \pi \epsilon_0 d_{12}^2 }$

5. anonymous

OK, I have a drawing and labelled. In the formula, is that the equivalent of kQ1Q2/r^2

6. JamesJ

Now $$F_{12}$$ is in the negative y direction; $$F_{14}$$ is in the positive x direction; and $$F_{13}$$ in the diagonal direction given. Write all of that out in vector notation and then find the magnitude of the sum of the three vectors. Then by symmetry, the magnitude of the charge on the other three points is the same.

7. JamesJ

**magnitude of the _force_ on the other ... [not charge]

8. anonymous

OK I am going to try to work on it and see what I can find my answer, I may be back.

9. JamesJ

It's a bit of computational pain.

10. anonymous

I can tell.