Coulomb's Law (Electric Force) Video Lessons

Concept

Problem: A 2.4 nC charge is at the origin and a -4.8 nC charge is at x = 1.1 cm .Part AAt what x -coordinate could you place a proton so that it would experience no net force?Part BWould the net force be zero for an electron placed at the same position?NoYes

FREE Expert Solution

Coulomb's law:

$\overline{){\mathbf{F}}{\mathbf{=}}\frac{\mathbf{k}{\mathbf{q}}_{\mathbf{1}}{\mathbf{q}}_{\mathbf{2}}}{{\mathbf{r}}^{\mathbf{2}}}}$

(a)

For the force to be zero,

ΣF = 0

The proton will be attracted to the negative charge and repelled by the positive charge. These forces will act in opposite directions if the proton is not placed between the two charges. The proton should also be placed closer to the charge with a smaller magnitude of charge.

Thus, the proton should be on the negative x-axis. As such it will be far away from the negative charge and closer to the positive charge.

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Problem Details

A 2.4 nC charge is at the origin and a -4.8 nC charge is at x = 1.1 cm .

Part A

At what x -coordinate could you place a proton so that it would experience no net force?

Part B

Would the net force be zero for an electron placed at the same position?

• No
• Yes