## Finding an unknown charge

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

A right triangle is shown below. The charge on the right is unknown, but the electric field shown is only in the –x direction.
a. What is the unknown charge?
b. What is the magnitude of the electric field?

2. Relevant equations

3. The attempt at a solution
I have no idea how to start this problem. I have just been staring at it for 20 minutes. I would really appreciate any help.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution
Attached Thumbnails

 PhysOrg.com science news on PhysOrg.com >> Ants and carnivorous plants conspire for mutualistic feeding>> Forecast for Titan: Wild weather could be ahead>> Researchers stitch defects into the world's thinnest semiconductor
 You have not posted any relevant equations. I think a good starting point would be looking for an equation for the electric field due to a point charge. As you have explained the electric field is in the -x direction. Would this mean that there is no y component at the point in question?

 Tags charges, coulomb's law