physics!!!!!
posted by Donna on .
A small spherical insulator of mass 8.00*10^2kg and charge +6.00*10^7C is hung by a thin wire of negligible mass. A charge of 9.00*10^7C is held 0.450m away from the sphere and directly to the right of it, so the wire makes an angle with the vertical. Find (a) the angle and (b) the tension in the wire.
I NEED HELP WITH THIS PROBLEM!!!!THANKS A LOT!!!!!!!

You have to assume the small spherical insulator is a point charge.
The force horizontal is given by coulombs law, so looking at the diagram,
TanTheta=horizontalforce/vertical force.
Of course, the vertical force is mg.
Tension in the wire? SinTheta=horizonalforce/tension.