29: Problem 29.9

PART A:
What is the direction of the electric field at the dot in the figure?

SOLUTION: 
placing the x axis horizontally through the point, it can be figured that V(x) = 10000x
E(x) = -dV(x)/dx so E(x) = -10000 V/m
this means that, based on our imposed axis, the direction of the electric field is to the left

PART B:
What is the magnitude of the electric field at the dot?

SOLUTION:
We already figured this out in the last part, and it is 10000 V/m