Question

A 0.13 g plastic bead is charged by the addition of 1.0Ã1010 excess electrons. what electric field eâ (strength) will cause the bead to hang suspended in the air?

Answer 1

The working equation for this is: E = F/Q, where E is the strength of electric field, F is the force and Q is the charge. The force is equal to:

F = mg = (0.13/1000 kg)(9.81 m/s²) = 1.2753×10⁻³ N

The charge of he excess electrons is equal to:
Q = (-1.6021766208×10⁻¹⁹ C/electron)(1×10¹⁰ electrons)
Q = -1.6021766208×10⁻⁹ C

E = 1.2753×10⁻³ N/-1.6021766208×10⁻⁹ C
E = -795,979.66 N/C