Final answer:
The electric field (Ex) at x = 0 m is 0 V/m.
Step-by-step explanation:
The electric potential along the x-axis is given by V = 200x² V, where x is in meters. To find Ex at x = 0 m, we need to determine the electric field at that point. The electric field (Ex) is the negative derivative of the electric potential (V) with respect to x. So, taking the derivative of V with respect to x, we get Ex = dV/dx = 400x V/m.
Since we are evaluating at x = 0 m, the electric field Ex will be zero at that point. Therefore, Ex at x = 0 m is equal to 0 V/m.