So I was given some questions as practice, and I cant seem to do them. Here is a link to the questions:
http://i.imgur.com/ZmkqCAV.jpg (the answers are in square brackets)
Ive only been able to calculate Q3 and Q2 so far. I would really especially like help with Q1. Ive been stuck on it for ages.
Ive been told this would be helpful: http://i.imgur.com/nmrsk2E.jpg
The Attempt at a Solution
Ive been stuck on Q1 for ages. Ive been playing around with F = k q1q2/r^2 but thats not getting me anywhere.
For Q2: I used E = kq/r^2 for q1 and q2. Subtracting the answers gave me -225x10^3, which is somewhat equal to 2.3x10^5. Ive got no idea on how to get the j vector component though.
Edit: I just got the j vector. Pythag and then the formula above got it.
I have no idea where to begin for Q4
ANY help appreciated. Thank you