Question:

Two point charges, Q1 = +2 × 10^-6 C and Q2 = -5 × 10^-6 C, are placed 2 meters apart in a vacuum. Calculate the magnitude of the electric force between them.

Answer:

The magnitude of the electric force between two point charges can be calculated using Coulomb's law. Coulomb's law states that the magnitude of the electric force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

The formula for Coulomb's law is:

F = k * (|Q1| * |Q2|) / r^2

Where F is the magnitude of the electric force, k is the electrostatic constant (k = 9 × 10^9 N m^2/C^2), |Q1| and |Q2| are the magnitudes of the charges, and r is the distance between the charges.

Plugging in the values, we get:

F = (9 × 10^9 N m^2/C^2) * [(2 × 10^-6 C) * (5 × 10^-6 C)] / (2 m)^2

Simplifying further:

F = 9 * 2 * 5 * 10^-11 N

F = 90 * 10^-11 N

F = 9 × 10^-10 N

Therefore, the magnitude of the electric force between the two charges is 9 × 10^-10 N.