PhysicsLAB: Coulomb's Law: Beyond the Fundamentals

In this lesson we will look at more advanced problems beyond the basic proportional relationships we have already studied using Coulomb's Law,

Refer to the following information for the next three questions.

Three point charges are placed along the x-axis. A +5 µC charge is located at the origin, a +2 µC charge is located 30 cm to its right, and a -4 µC is located at 50 cm.

	Calculate the magnitude and direction of the force exerted on the +2 µc charge by the +5 µC charge.

	Calculate the magnitude and direction of the force exerted on the +2 µc charge by the -4 µC charge.

	What is the magnitude and direction of the net force on the +2 µC charge?

Refer to the following information for the next four questions.

Two point charges are placed along the x-axis. A +5 µC charge is located at the origin and a -4 µC is located at 50 cm. Our task is to determine where the +2 µC charge could be placed so as to feel no electrostatic force.

	Why should the +2 µC charge be placed to the right of the -4 µC charge and not to the left of the +5 µC charge?

	Develop and expression for the magnitude of the force exerted on the +2 µc charge by the -4 µC charge.

	Develop an expression for the magnitude of the force exerted on the +2 µc charge by the +5 µC charge.

	What value(s) of x will place the +2 µC charge in equilibrium?

Refer to the following information for the next six questions.

Examine the following diagram which shows four charges that have been placed on the corners of a square 50 cm on each edge. Our task is to determine the net force on the 2 µC charge.

	Sketch in the forces acting on the 2 µC charge.

	Calculate the magnitude and direction of F_3,2.

	Calculate the magnitude and direction of F_5,2.

	Calculate the magnitude and direction of F_-4,2.

	Calculate the net force on the 2 µC charge in both the x-direction and the y-direction.

	Calculate the final magnitude and direction of the force on the 2 µC charge.