Answer:
The third charged particle needs to be positioned at x = 0.458 m = 45.8 cm
Explanation:
To address this inquiry, we refer to Coulomb's law:
Two point charges (q₁, q₂) spaced apart by a distance (d) impart a mutual force (F) with a magnitude defined by the equation:
Formula (1)
F: Electric force in Newtons (N)
K: Coulomb's constant in N*m²/C²
q₁, q₂: Charges quantified in Coulombs (C)
d: distance in meters (m)
Equivalence
1μC= 10⁻⁶C
1m = 100 cm
Information
K = 8.99 * 10⁹ N*m²/C²
q₁ = +5.00 μC = +5.00 * 10⁻⁶ C
q₂= +7.00 μC = +7.00 * 10⁻⁶ C
d₁ = x (m)
d₂ = 1-x (m)
Problem analysis
Refer to the accompanying graphic.
We assume a positive charge q₃, thus F₁₃ and F₂₃ exhibit repulsive forces that need to be equivalent so the resultant force is zero:
Utilizing equation (1), we will determine the forces F₁₃ and F₂₃


F₁₃ = F₂₃
We eliminate k and q₃ from both sides


We discard 10⁻⁶ from both sides




We solve for the quadratic equation:


Choosing x₂ results in F₁₃ and F₂₃ acting in the same direction and unable to cancel each other, therefore we select x₁ as the accurate choice since at this stage the forces counteract each other.
x = 0.458m = 45.8cm