Two large parallel conducting plates are 17 cm apart and have charges of equal magnitude and opposite sign on their facing surfaces. an electrostatic force of 2.9 ✕ 10-15 n acts on an electron placed anywhere between the two plate (neglect fringing). (a) find the electric field at the position of the electron.

The electrostatic force acting on a charge q is given by

where E is the electric field's intensity.

In our problem, the particle is an electron, so its charge is . We know the intensity of the force, so we can find the magnitude of the electric field at the point where the electron is located:

where the negative sign means that the force and the electric field have opposite direction, because the charge is negative.

The charge of an ion with 55 protons and 52 electrons is +3. the reason is because protons are positive, and there are three more than the amount of negative electrons.