Answer to Question #329528 in Electricity and Magnetism for Terdo

Question

A small sphere with a mass of of 4.00 X 10-6 kg and carrying a charge of 5.00 X 10-8 C hangs

from a thread near a very large, charged insulating sheet, as shown below. The charge density on

the surface of the sheet is uniform and equal to 2.50 X 10-9 C/m2

. Find the angle of the thread.

Answer 1

$\theta=\arctan\frac{kq\sigma }{mg}=1.6°.$