Im getting 297 degrees but it is wrong? any idea what is the error?
I found the x and y component of the electric force. did tan(theta)=(ycomponent/xcomponent)
Thanks!

297 degrees seems about right.

are you sure its wrong?

Try entering 297 as -63 degrees since it says "Answer in degrees as an angle between -180 and 180 degrees".

This post was edited by X-PeRiMeNt on Jun 10 2013 08:50pm

yup, i put in the exact answer too. 297.0796

this. the angle seems correct without doing any calculations

i was looking at this site i found
question #6 is a similar problem. I have no idea what they did...
http://www.phys.ttu.edu/~huang24/Teaching/Phys2401/HWSolutions/HW1solutions.pdf

why -180?

probably because it is the smallest angle then (in absolute terms) and providing direction from the x-axis
+ going counterclockwise
- going clockwise

This post was edited by brmv on Jun 10 2013 09:16pm

because the problem asks you to put an angle between 180 and -180.

its a weird way to phrase it, but basically consider the upper half of the unit circle +180, and the bottom half of the unit circle -180. 180 and -180 are the same point.

so would you say that -63 is correct? i would think so too. since the vector components magnitude are in the 4th quadrant..?

if you found the angle to be 297, subtract that from 360. i get -81 degrees. that seems pretty close. let me know if that works