# Homework Help: Coulomb's Law and Vectors

1. Jun 16, 2004

### supermenscher

Can anyone help me with this one, its really giving me problems. u = 10^-6C

Three positive particles of charges 12.5uC at the corners of an equilateral triangle. The sides of the triangle are 0.17meters long. Calculate the magnitude and direction of the net force on each particle. Of the 3 positive particles, Q1 is at the top of the triangle, Q2 is the left side of the triangle, and Q3 is the right side of the triangle. Please help!!!

2. Jun 16, 2004

### JohnDubYa

What is it about the problem that gives you trouble? The concept of Coulombic force? Vector summation? Geometry?

3. Jun 16, 2004

### supermenscher

Basically the whole thing...I just can't get the grasp on how to do it. Could you please help me? Thanks

4. Jun 16, 2004

### arildno

If you had just 2 charged particles, how would you find the force that acts upon one of them from the other, that is: what is the Coulomb force acting on a charged particle from another charged particle?

5. Jun 16, 2004

### supermenscher

could some one explain this a little further, that would really help me. thanks

6. Jun 16, 2004

### Gokul43201

Staff Emeritus
Consider Q1. It experiences forces from Q2 and Q3. Each of these forces may be calculated using Coulomb's Law - in fact, they have the same magnitude. The directions of these forces are found by extending the lines Q2Q1 and Q3Q1 and sticking little arrowheads on their ends, pointing away from Q2 and Q3. OR, Q2 and Q3 try to push Q1 away from them. Now you need to find the resultant force. You can do this by resolving each of the two forces into vertical and horizontal components. In this case, the horizontal components are equal, but in opposite direction, so they cancel each other. So you are left with twice the vertical component of one force.