Three point charges ( 3 n C .6 n C ) and ( 9 n C ) are placed at the comers of an equilateral triangle of side ( 0.1 ~m ). The potential energy of the system is

Step-by-step solution

Potential energy is given as ( U= 1 4 ₀ q₁ q₂ r ) The three charges are placed at the corners of an equilateral triangle as shown in the following figure. The potential energies of the three charges are given as [ aligned U₁ &= 1 4 ₀ 3 n C 6 n C 0.1 = 1 4 ₀ 18 10⁻¹⁸ 0.1 U₂ &= 1 4 ₀ 6 n C 9 n C 0.1 = 1 4 ₀ 54 10⁻¹⁸ 0.1 U₃ &= 1 4 ₀ 9 n C 3 n C 0.1 = 1 4 ₀ 27 10⁻¹⁸ 0.1 aligned ] Therefore, potential energy of the system is given as [ array l U=U₁+U₂+U₃= 1 4 ₀ [ 18+54+27 0.1 ] 10⁻¹⁸ = 9 10⁹ 99 10⁻¹⁸ 0.1 =8910 10⁻⁹ ~J a