A 10.0 g insulating sphere with a net charge of + 2.0 nC is suspended between two plates of a charged, square capacitorof sides 10 cm and plate separation 10 cm. What is the charge on the top capacitor plate?

= 4.34 * 10⁻⁶C

Explanation:

Net Force = W - F (electric) = 0

where, F (electric) = qE

qE = qV/d

V = potential between plate

V = Q/C

Q = charge on plate

C = capacitance

C = E₀A / d

F (electric) = qQ/E₀A

W = F (electric)

mg = qQ/E₀A

Q = mgE₀A / q

(A) area of plate = (0.10m) ² = 0.01m²

m = 10 * 10⁻³kg

E₀ = 8.85 * 10⁻¹²C²N⁻¹m⁻²

q = 2 * 10⁻⁹c

Q = ((10 * 10⁻³) (9.8) (8.85 * 10⁻¹²) (0.01)) / (2 * 10⁻⁹)

Q = 4.34 * 10⁻⁶C