ok i have been thinking about this problem for a lil bit now and i think i have it correct but i would just like to double check:(adsbygoogle = window.adsbygoogle || []).push({});

(a) twelve equal charges, q, are situated at the corners of a regular 12-sided polygon (for instance, one on each numeral of a clock face). What is the net force on a test charge Q at the center?

(b) suppose one of the 12 q's is removed (the one at 6 o'clock). what is the force on Q?

for (a) i was thinking that would end up cancelling each other out leaving no net force on Q.

for (b) all the charges would cancel one another except for the charge at 12 o'clock because there would be no charge at 6 o'clock the cancel it out so the force on Q would simply be k*q*Q/r^2 where r is the distance from q at 12 o'clock to Q.

i was just wondering if this was the correct way to think about this problem and if im off the mark a bit with it it would be great if someone could help me out a bit..

thanks

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# EM (coulombs law)

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