In a certain region of space the electric potential is V= 5x-3x^2y+2yz^2. Find the expressions for the x,y,z compenents of the electric field in this region. What is the magnitude of the field at the point P, which has coordinates 1,0,-2)m?

I don't know how to start this problem..is there a formula to use? Any help would be greatly appreciated!

1 answer

The E field in direction x is
Ex = -dV/dx (partial deriviative)
and similarly for Ey and Ez
Ey = -dV/dy
Ez = -dV/dz = -4yz

Do the other two partial derivatives, and then plug in the appropriate x,y,z values for that point.

As the final step,
|E| = sqrt(Ex^2+Ey^2+Ez^2)