Question

A tiny, glass sphere has a charge of +10.9 nC. A metal ball bearing, which is 4.00 cm above the glass sphere, experiences an electric force of magnitude 0.0130 N. What is the ball bearing's charge? Assume it is positive.

Answer 1

2.12 × 10⁻⁷ C

Step-by-step explanation:

Given:

Charge on the glass sphere, Q = 10.9 nC = 10.9 × 10⁻⁹ C

Distance between the glass and the metal sphere, r = 4.0 cm = 0.04 m

Force experienced by the metal sphere, F = 0.0130 N

let the charge on the metal sphere be 'q'

Now,

the force due to a charge on the other charge is given as:

`F=(kQq)/(r^2)`

where,

k is the coulomb's constant = 9 × 10⁹ N.m²/C²

on substituting the values in the formula, we get

`0.0130=(9*10^9*10.9*10^(-9)*\q)/(0.04^2)`

or

q = 2.12 × 10⁻⁷ C