Recent content by Azura

I'm sorry. I made got this drawn below. In "a" both charges are the same signal (positive) and in "b" one is positive and the other is negative. As shown in the figure, I don't understand why the total field is the way it is... Like, in "a" we have "2q cosθ" because the said horizontal...

1) Imagine you have a clock but in each number you have a charge "q". If I have a test charge Q at the center, then by simetry, the net force on Q is zero. I imagined like, 1 cancels 7, 2 cancels 8, etc... But then, if I have a polygon with 13 sides, with a test charge Q, the net force also...