Three charges are located at 100-m intervals along a horizontal line: a charge of -3.0 C on the left, 2.0 C in the middle, and 1.0 C on the right. What is the electric field E on the horizontal line halfway between the -3.0 C and 2.0 C charges?

Question

Quizplus · Accepted Answer

To find the electric field at the midpoint between the -3.0 C and 2.0 C charges, we can use the principle of superposition to find the electric fields due to each individual charge and then add them together. The electric field due to each charged particle is given by Coulomb's law:
E = k * q / r^2
where k is Coulomb's constant, q is the charge, and r is the distance from the charge.

The electric field due to the -3.0 C charge at the midpoint is:
E1 = k * (-3.0 C) / (50 m)^2 = -1.08 × 10^8 N/C to the right

The electric field due to the 2.0 C charge at the midpoint is:
E2 = k * (2.0 C) / (50 m)^2 = 3.60 × 10^7 N/C to the left

The net electric field at the midpoint is the vector sum of these two fields:
E = E1 + E2 = (-1.08 + 0.36) × 10^8 N/C = -0.72 × 10^8 N/C = -1.8 × 10^7 N/C to the left.

Therefore, the answer is C, 1.8 × 10^17 N/C to the left.

Three Charges Are Located at 100-M Intervals Along a Horizontal