In the diagram, Q = 12 C, point P is at x = - 30 cm, charge 2Q is at y = + 35 cm and charge -Q is at y = - 35 cm. Determine the electric field and potential at point P.

In the diagram, Q = 12 C, point P is at x = - 30 cm, charge 2Q is at y = + 35 cm and charge -Q is at y = - 35 cm. Determine the electric field and potential at point P. + 2