# Net Force of a Charge

1. May 30, 2013

### aChordate

1. The problem statement, all variables and given/known data

The drawing shows three point charges fixed in place. The charge at the coordinate origin has a?
q1 = +8.50 µC; the other two have identical magnitudes, but opposite signs: q2 = -5.00 µC and q3 = +5.00 µC.

http://img66.imageshack.us/my.php?image=p1818mv9.gif

(a) Determine the net force (magnitude and direction) exerted on q1 by the other two charges.

(b) If q1 had a mass of 1.50 g and it were free to move what would be its acceleration?

2. Relevant equations

F12=k|q1||q2|/r2

F13=k|q1||q2|/r2

3. The attempt at a solution

F12= +2.128*1023

F13= -+2.128*1023

cos(23°)= Fx/+2.13*10^23

Fx= 1.96*1023

cos(23°)= Fy/-2.13*10^23

Fy= -1.77 *1046

Before I go any further, I wanted to make sure I am doing this right since I am kind of rusty. If anyone could check, it would be greatly appreciated.

2. May 30, 2013

### Simon Bridge

Your attempt does not show any reasoning nor any working - so I cannot tell if you are doing this right or not.

Note: you can show the image in the post like this:

[Broken]​

You look like you've maybe tried to break the forces into x and y components - but why not just draw the vectors head-to-tail? You can see by inspection how their magnitudes and directions are related - which should tell you the direction of the total force without having to do any trig.

Last edited by a moderator: May 6, 2017