How much work must be done to bring three electrons from a great distance apart to 3.5*10-10 m from one another (at the corners of an equilateral triangle) ?

1.97 * 10⁻¹⁸J

Explanation:

Charge of an electron q = - 1.9 * 10⁻¹⁹C

Length of one side of the equilateral triangle at whose corners electrons are placed d = 3.5 * 10⁻¹⁰m

Coulomb constant k = 8.99 * 10⁹Nm²/C²

electrostatic potential = (3 kq²) / d

= (3 * 8.99 * 10⁹ * (-1.6 * 10⁻¹⁹) ²) / 3.5 * 10⁻¹⁰

= 1.97 * 10¹⁸J