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# electric field magnitude at mid point between 2 charges

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Why bother with a post grad? Are they even worth it? Have your say! 26-10-2016
1. Look at those attachments when calculating the magnitude of the electric field at the mid point between those charges when do i have to take in the direction of the e field? So i find net by finding the difference or the sum.
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2. (Original post by jonnypdot)
Look at those attachments when calculating the magnitude of the electric field at the mid point between those charges when do i have to take in the direction of the e field? So i find net by finding the difference or the sum.
only the mid point between the positive and negative charges will have a magnitude, the midpoints of the other two fields have the field lines cancelling each other out at the midpoint.
You would have to find the electrostatic force, F between them and then use E=F/Q
3. (Original post by The Rohan)
only the mid point between the positive and negative charges will have a magnitude, the midpoints of the other two fields have the field lines cancelling each other out at the midpoint.
You would have to find the electrostatic force, F between them and then use E=F/Q
sorry forgot to say charges are not equal, also cant i use g=q/kr^2 at mid point and add them?
4. (Original post by jonnypdot)
sorry forgot to say charges are not equal, also cant i use g=q/kr^2 at mid point and add them?
yeah if the charges aren't equal then find the difference between them and that will be the charge, Q, at the midpoint
Then wouldn't you use F=Qq/4pi(8.85x10^-12)(r^2) to find F
and then use E=F/Q and that should be fine
have you got the answers and figures to go with the question?
5. (Original post by The Rohan)
yeah if the charges aren't equal then find the difference between them and that will be the charge, Q, at the midpoint
Then wouldn't you use F=Qq/4pi(8.85x10^-12)(r^2) to find F
and then use E=F/Q and that should be fine
have you got the answers and figures to go with the question?
no but i once did a question between 2 charges and the ms showed you that they added the value for E at mid point of both charges
6. (Original post by jonnypdot)
no but i once did a question between 2 charges and the ms showed you that they added the value for E at mid point of both charges
Could I see the question?
7. (Original post by The Rohan)
Could I see the question?
here
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