A small spherical insulator of mass 4.95 × 10-2 kg and charge +0.600 C is hung with a thin wire of negligible mass. A charge of -0.900 C is held 0.150 m away from the sphere and directly to the right of it, so the wire makes an angle by the vertical (see the drawing). Discover (a) the angle and (b) the tension in the wire.