Final answer:
To determine the x and y components of the net electric field at a point a height y=0.400m above the ground, you need to consider the electric field at that point. The x component of the net electric field will be the same as the electric field at that height, and the y component will be zero.
Step-by-step explanation:
To determine the x and y components of the net electric field at a point a height y=0.400m above the ground, you need to consider the electric field at that point. The electric field at a point due to a uniformly charged plane in the xy-plane can be found using Gauss's law formula. The electric field is given by E = 2πkσa, where k is the Coulomb constant, σ is the charge density, and a is the distance from the plane. Here, you need to substitute the given values into the formula to calculate the electric field at that height. The x component of the net electric field will be the same as the electric field at that height, and the y component will be zero. Hence, the x and y components of the net electric field can be determined.