Coulomb's Law (Electric Force) Video Lessons

Concept

# Problem: Three point charges are arranged on a line:Charge q3 = +5.00×10-9 C and is at the origin.Charge q2 = −3.00×10-9 C and is at x = +4.00cm. Charge q1 is at x=+2.00cm.What is the magnitude and sign (+ or −) for q1 if the net force on q3 is zero?

###### FREE Expert Solution

Coulomb's law:

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

Δx13 = 2.00 cm(1m/100cm) = 0.02 m

Δx23 = 4.00 cm(1m/100cm) = 0.04 m

The sum of forces on q3 should be zero.

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###### Problem Details

Three point charges are arranged on a line:
Charge q3 = +5.00×10-9 C and is at the origin.
Charge q= −3.00×10-9 C and is at x = +4.00cm.
Charge q1 is at x=+2.00cm.
What is the magnitude and sign (+ or −) for q1 if the net force on q3 is zero?