Consider three charges arranged as follows. An 8.5nC charge is located at the or
ID: 2048160 • Letter: C
Question
Consider three charges arranged as follows. An 8.5nC charge is located at the origin (0,0), a 3.2nC charge is located along the positive x-axis .634m away (.643,0), and a -4.3nC charge is located along the negative y-axis .39m away (0,-.39). The question asked for the net electric force on the charge at the origin which I answered correctly (it was 2.244339878+10^-6N) and the angle of that force which was -105.7272049degrees. It then asks What is the magnitude of the net electric fieldat the position of the charge at the origin? Answer in units of N/C
I tried .264039986 N/C ; 3.106352773*10^10 N/C ; and 252.17302 N/C and they were all wrong. Can anyone help? I don't know what I'm doing wrong, please show all steps, Thanks!
Explanation / Answer
You are very close in on of your answers, but just messed up a little on the units.
You have already done all of the vector addition to find the force. You indicate that the force is 2.244339878 X 10-6 N
Assuming that is correct, as you mentioned, then the solution to the electric field is quite simply. No need to to any vector addition all over again.
Simply use the formula F = qE where q is the charge in question (the one at the origin)
E = F/q
E = (2.244339878 X 10-6 N) / (8.5 X 10-9 C)
E = 264 N/C
My guess is that in your first answer you didn't take into consideration that 8.5 nC means nano Coulombs and that nano is 10-9.
Don't beat yourself up too bad. It looks as if you were doing everything correctly except for the order of magnitude. Its a common mistake.