Consider a large, thin, electrically neutral conducting plate in the xy-plane at z = 0 and a point charge q on the z-axis at distance z_Charge = d. What is the electric field on and above the plate? Although the plate is neutral, electric forces from the point charge polarize the conducting plate and cause it to have some complex distribution of surface charge. The electric field and potential are then a superposition of fields and potentials due to the point charge and the plate's surface charge. That's complicated! However, it is shown in more advanced classes that the field and potential outside the plate (z greaterthanorequalto 0) are exactly the same as the field and potential of the original charge q plus a "mirror image" charge - q located at z_image = -d. A +15 nC point charge is 4.0 cm above a large conducting plate. What is the electric field strength at the surface of the plate 2.0 cm away from being directly beneath the point charge? Express your answer with the appropriate units.