Question

Three equal point charges, each with charge 2.00 μC , are placed at the vertices of an equilateral triangle whose sides are of length 0.350 m . What is the electric potential energy U of the system? (Take as zero the potential energy of the three charges when they are infinitely far apart.) Use epsilon_0 = 8.85×10−12 F/m for the permittivity of free space.

Answer 1

U = 3.08 10¹¹ J

Step-by-step explanation:

Let's apply to our case

U = k q₁q₂/ r₁₂ + k q₂q₃ / r₂₃ + k q₁q₃ / r₁₃

Let's look for distances, in an equilateral triangle all sides are equal

r₁₂ = r₂₃ = r₁₃ = L

In the exercise they give the value of the charges and the side of the triangle

q₁ = q₂ = q₃ = 2.00 C

L = 0.350 m

In this case all the charges are equal and the distances are also the same, the formula is

U = k 3 q² / L

Let's calculate

U = 8.99 10⁹ 3 4/0.350

U = 3.08 10¹¹ J