HI there. I am revising for my A level Physics exam in January. I have printed out past paper questions, but have no qnswers to them! I have worked through this question and was wandering if anyone could check to see I have done it correctly.
Any help greatly appreciated.
Two point charges, each of magnitude 5x10^-6C, are placed horizontally 50mm apart at points A and B respectively.
Calculate the force exerted on a point charge of 3x10^-6C at a point P, which is 20mm from A and 30mm from B, in the cases when:
i) both charges A and B are positive (my answer 11.25N)
ii) A is positive and the charge at B is negative (my answer 2.25N)
Thank you very much for assistance!
Ok, well I worked out the electric field strength due to A (2.25x10^6N/C) and then the same for B (1.5x10^6N/C)
Then I worked out the force due to A (6.75N) and then for B (4.5N) and added them together giving 11.25N for part i
For part ii, I said that since B was negative, it should be subtracted from A giving 2.25N for part ii.
Thanks again for your help.