Question

Three point charges q - 2 q - 2 q are placed at the vertices of an equilateral triangle of side are the work done to increase their separation to our is

Answer 1

Answer:

The work done will be zero.

Explanation:

Since the formulate of the potential energy is k(q1)(q2)/r. So, the initial electrostatic potential energy will be = k(q)(-2q)/r + k(-2q)(-2q)/r + k(-2q)(q)/r

= -2kq²/r + 4kq²/r - 2kq²/r

Which will be equal to.

= 0

Again, the final electrostatic potential energy will be  = k(q)(-2q)/2r + k(-2q)(-2q)/2r + k(-2q)(-q)/2r.

= -2kq²/2r + 4kq²/2r - 2kq²/2r.

= -kq²/r + 2kq²/r - kq²/r.

Which also on solving gives us 0.

So, we know that the energy conservation theorem states that the change in the potential energy will be equal to the work which is done by the external force. So, the work which is done by external force is the change in potential energy which is equal to zero.