Question

The electric force between two charged vinyl balloons is 3.0 × 10-3 newtons. If the distance between them is 6.0 × 10-2 meters and the charge of one vinyl balloon is 3.3 × 10-8 coulombs, what is the charge on the other vinyl balloon? (k = 9.0 × 109 newton·meter2/coulombs2) 3.3 × 10-8 coulombs 3.6 × 10-8 coulombs 4.8 × 10-8 coulombs 6.0 × 10-8 coulombs 3.3 × 10-3 coulombs

Answer 1

The electric force between two objects can be understood by looking at Coulomb's Law. The law states that the electric force is directly proportional to the charges of the 2 objects, and inversely proportional as the square of the distance. This is shown below:

F = (k * Q1 * Q2) / d^2

Where: k = proportionality constant; Q1 = charge of object 1; Q2 = charge of object 2; d = distance between objects.

Given:

F = 3.0 × 10^-3 N
Q1 = 3.3 × 10^-8 coulombs
Q2 = ?
d = 6.0 × 10^-2 m
k = 9.0 × 10^9

Substituting:

3 x 10^-3 = (9 x 10^9 * 3.3 x 10^-8 * Q2) / (6 x 10^-2)^2
[(3 x 10^-3) * (6 x 10^-2)^2] / [(9 x 10^9) * (3.3 x 10^-8)] = Q2
Q2 = 3.636 x 10^-8 coulombs