This is where the vector diagram is important. We know that both forces pulling on two are in the positive y and positive x direction. Thus, both of the forces have to be positive; having a negative number flips that sign. Thus, you have to know the direction of the forces so your answer makes sense. Unfortunately, that means you can't just plug the numbers into the formula as-is and get the right answer.
I am impressed by this lecture... honestly
just perfect . Thanks so much for all the great lectures
very helpful :) thank you!
Best!
why do you change the sign from - to + on q2?
This is where the vector diagram is important. We know that both forces pulling on two are in the positive y and positive x direction. Thus, both of the forces have to be positive; having a negative number flips that sign. Thus, you have to know the direction of the forces so your answer makes sense. Unfortunately, that means you can't just plug the numbers into the formula as-is and get the right answer.
Why do we have to assume that all charges are stationary?
if they aren't the charges are going to move which well affect the angle.
thanx