Question

3 equal charges (all +Q) are located at A, B and C. ABC is an equilateral triangle with sides d. Point A is located at (0,0), point B at (d,0), point C at (d/2,d3√/2). Point P is inside the triangle such that AP=BP=CP. What is the electric field at P - we want the magnitude and the direction.

Answer 1

Symmetry.
Draw a diagram to show the three electric fields as vectors.
Now construct a triangle of vectors.
What is the resultant vector?