1. Four identical point charges (q = +30.0 µC) are located on the corners of a rectangle. The dimensions of the rectangle are L = 70.0 cm and W = 20.0 cm. Calculate the magnitude and direction of the net electric force exerted on the charge at the lower left corner by the other three charges.(adsbygoogle = window.adsbygoogle || []).push({});

>> I'm not sure what I did wrong with this one. Basically, what I did was use F=ke[(|q1| |q2|)/r^2] for the three sides effecting the lower left corner one. Then I took these forces and broke them into x and y components, added them together, and then used the pythagorean theorem to find F. I got an answer of 2.15e10. Then for the direction, I said it would be 45 degrees counter clockwise from the x-axis, because since they are all positive charges, they would repel each other.

Any idea what I'm doing wrong???

2. Two small silver spheres, each with a mass of 9.00 g, are separated by 1.00 m. Calculate the fraction of the electrons in one sphere that must be transferred to the other to produce an attractive force of 2.00e4(about 2 tons) between the spheres. (The number of electrons per atom of silver is 47, and the number of atoms per gram is Avogadro's number divided by the molar mass of silver, 107.87 g/mol.)

>> I have absolutely no idea how to start this one. The only thing I can think of would be F=ke[(|q1||q2|)/r^2], but I don't think that's right... argh!!!

3. This one goes with a picture -> q1 and q2 are on the x axis seperated by 1.00 m. (q1 = -2.7 µC, q2 = 6.00 µC), determine the point (other than infinity) at which the electric field is zero.

>> All I know with this is that the point is going to have to be to the left of q1. But I don't know how to find the exact point!!

Any help would be greatly appreciated!!! I'm going insane

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# Homework Help: Electrical Forces

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