Ok, the question is: you have a uniformly charged rod of length 16.6cm with charge -22.3 microCouloumbs, determine the magnitude of the electric field along the axis of the rod at a point 18.9358 cm from the center of the rod, answer in units of N/C(k is given as 8.98755 x 10^9)(adsbygoogle = window.adsbygoogle || []).push({});

Soooo then, I converted everything(hopefully correctly)16.6cm =.166m, -22.3 microC=-2.23x10^-5, 18.9358cm=.189358m. Yay. Using the formula dE=k(dQ/r^2), I found dQ to be Q/L(dl), or charge/length(dl), which I found to be -1.34337x10^-4(which I'll say is &) times dl, so taking the integral and taking out all the constants, I got k&/r^2 S(dl), where S is the integral sign, and I took it over the length of the rod which was .166, so ultimately I get k&.166/r^2 and I'll spare the long number typing. Now, to get r I subtracted .083 from .189358, I ALSO just did the given distance when I got the wrong answer(online hw, yay)and both haven't worked. The answers that have failed have been 1.77176x10^7, and the negative of that, and 5.58956x10^6(which I got using the dist from the center as given)I haven't tried the negative yet because I lose points everytime I get it wrong, and was wondering if that was possibly right? I was pretty sure I was doing it right the first way but I've quadruple checked everything and it's still wrong

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# Homework Help: Electricity question that I thought I had but I don't

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