# Homework Help: Electromag problem

1. Nov 5, 2007

### magicuniverse

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

Three particles with euqal positive charge q are placed at three corners of a square side d.

a) what is the force on a postive charge q0 placed at the center of the square?

b) what would be the force on q0 if it were placed on a vacant corner?

2. Relevant equations

I think you have to use gausses law but am not sure and do not know how to do this if i did.

3. The attempt at a solution

N.A i dont have a clue, some guidance would be hugely appretiated.

2. Nov 5, 2007

### Kurdt

Staff Emeritus
Force is a vector quantity. If you work out the force on the q0 charge from the other three and the direction in which they are acting you should be able to find the resultant force.

3. Nov 5, 2007

### magicuniverse

Yes but I do not understand HOW you would get the forces and even if i did wouldnt kno how to resolve them.

4. Nov 5, 2007

### Kurdt

Staff Emeritus
What have you been learning? The force is given by coulombs law.

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elefor.html#c1

I'm not sure if i can explain how to resolve forces if you have no indication of how to deal with them. There is a tutorial at the following web site.

http://www.mathcentre.ac.uk/students.php/all_subjects/mechanics/newton/resources/607 [Broken]

Last edited by a moderator: May 3, 2017
5. Nov 6, 2007

### magicuniverse

Thanks that was so helpful. Also sorry for putting up with me, I have done this stuff in class but have had a really bad sports injury recently which has meant ive been spending more time with surgeons looking at scans than in lectures so the basics are confusing.