Calculating Charge and Tension in a System of Suspended Spheres

[awill2007]

Homework Statement

A set of charged spheres were held suspended above another sphere with a charge of .1 C. The spheres are held by thin nylon strings (assume zero mass). Determine the charge on the suspended spheres and the tensions T1, T2, and T3.

The drawing looks like an upside down triangle with the top two spheres mass = .2 kg

the lengths of the triangle are .7m and .7m for the sides, and .6 for the base.

Homework Equations

I have no idea how to find tension. The charges are found using electric force eqn?

The Attempt at a Solution

i'm kinda lost, so i can't attempt until i have a general direction.

Please help me!

 

[turdferguson]

Draw out free body diagrams. Are the spheres on Earth with weight?

 

[awill2007]

here is the problem...

 

[awill2007]

can anyone help please?