A point charge of -3.0𝞵C is placed at the origin of coordinates. Find the electric field at the point x=5.0m on the x-axis.

Question

A point charge of -3.0𝞵C is placed at the origin of coordinates. Find the electric field at the point x=5.0m on the x-axis.

Answer 1

Electric field intensity is defined as the force exerted on a unit positive charge by another charge. The formula is

F/Q1 =E = k Q2/r² where k is the Coulomb constant (8.99 x 10⁹ Nm²C^*2), Q1 the unit positive charge, Q2 the charge creating the field, and r the distance between the charges.

Substituting the known quantities into the equation

E = 8.99 x 10⁹ Nm²C-² (-3 x 10^-6 C) / 25.0 m² = -1079 N/C directed toward the origin.