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## Homework Statement

At a distance

*D*from a very long (essentially infinite) uniform line of charge, the electric field strength is 1000 N/C. At what distance from the line will the field strength to be 4000 N/C?

## Homework Equations

E=kq/r

^{2}

## The Attempt at a Solution

I know that E is inversely proportional like so: E~1/r

^{2}

hence by rearranging for 'r' I got: r~sqrt(1/E)

then I plugged in 4E because 4000 N/C is four times 1000 N/C: r~sqrt(q/4E)

and I got r~E/2 but the answer is E/4 and I don't know how?

Thanks in advance