Question-Electrostatics-Point charge and uncharged plate

[GPhab]

Homework Statement

A point charge is placed at a distance "d" from a huge uncharged metal (slab or plate).[Comment: I'm not sure. Work out both cases]. Calculate the force with which the charge attracts the plate.

Homework Equations

The Attempt at a Solution

The field inside the slab is zero. Imagine a plate and a point charge (say +Q) is placed to its right. A negative charge appears on the side facing the charge and positive charge on other side. Calculating the charge density is not a problem. As the field due to plates of charge doesn't vary with distance(they are small compared to the dimensions in this case), there is no net field due to the positive and negative induced charge surfaces at the place where the point charge is. So the point charge won't experience any force. But we were told that the force IS NON-ZERO. For the plate case, the positive and negative induced charges are at the same place and the force is zero. Help!

 

[GPhab]

Sorry. I found that this is a standard example demonstrating some technique called "method of images".

 

[baba89]

I would suggest that the homework statement needs to be clarified. It is unclear whether the point charge is placed at a specific distance from the plate or if it is placed at a specific distance from the slab. Depending on the placement of the point charge, the force it experiences may differ.

In the case where the point charge is placed at a specific distance from the plate, the force it experiences can be calculated using Coulomb's law, taking into account the distance between the point charge and the plate, as well as the magnitude of the charge on the plate. However, if the point charge is placed at a specific distance from the slab, the force it experiences may be zero, as the induced charges on the slab would cancel out the electric field from the point charge.

In order to accurately calculate the force between the point charge and the uncharged plate, further information is needed such as the placement of the point charge and the dimensions of the plate. Clarifying these details would lead to a more precise solution to the problem.