I need immediate help on these questions:.
2.a small plastic ball with a mass of 0.005kg is suspended from a thread and hangs in equilibrium as shown in the drawing below when a small rod with a 2 uC charge is brought to within 3mm of the ball
a)find the tension force in the string
b) find the charge on the plastic ball(including sign)
3.A parallel plate capacitor has a potential difference of 100 volts and a distance between plates of 1cm. A small charged particle with a mass of 2grams is suspended in mid-air between the plates
a)find the electrostatic force acting on the particle(including direction)
b) find the electric charge that exists on the particle(including the sign)
Please!!! Including explanation and answer!