Question

How much work must be done to bring three electrons from a great distance apart to within 9.0 × 10-10 m from one another (at the corners of an equilateral triangle)?

Answer 1

As we know that change in the potential energy of the system must be equal to the work done to bring the system of charges

here we know that

`U = 3(kq_1q_2)/(r^2)`

also here we have

`q_1 = q_2 = 1.6 * 10^(-19) C`

`r = 9 * 10^(-10) C`

now we will have

`U = (9 * 10^9 (1.6 * 10^(-19))^2)/((9* 10^(-10))^2)`

`U = 2.84 * 10^(-10) J`

So here work done to bring three charges at the vertices of a triangle is given as

`W = 2.84 * 10^(-10) J`