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

Answer:

2.12 × 10⁻⁷ C

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:

$F=\frac{kQq}{r^2}$

where,

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

on substituting the values in the formula, we get

$0.0130=\frac{9\times10^9\times10.9\times10^{-9}\times\q}{0.04^2}$

or

q = 2.12 × 10⁻⁷ C