Question

Consider the charges q,q and -q placed at the vertices of an equilateral triangle of each side l. The sum of forces acting on each charge is quora

Answer 1

Let's mark the charges as q1, q2 and q3 respectively.

The force on q1 is= (1/4.pi. epsilon)(q^2)/l^2 - (1/4.pi. epsilon)(q^2)/l^2 = 0

Similarly, the force on q2 is= (1/4.pi. epsilon)(q^2)/l^2 - (1/4.pi. epsilon)(q^2)/l^2 = 0

The force on q3 is = - (1/4.pi. epsilon)(q^2)/l^2 - (1/4.pi. epsilon)(q^2)/l^2 = - 2 (1/4.pi. epsilon)(q^2)/l^2.

Hence, the required sum of the forces = 0 + 0 - 2 (1/4.pi. epsilon)(q^2)/l^2 = - 2 (1/4.pi. epsilon)(q^2)/l^2