Two factors determine whether a substance is a solid, a liquid, or a gas: The kinetic energies of the particles (atoms, molecules, or ions) that make up a substance. Kinetic energy tends to keep the particles moving apart. The attractive intermolecular forces between particles that tend to draw the particles together.
The magnitude of the E-field decreases as the square of the distance from the charge, just like gravity.
Location ' x ' is √(2² + 3²) = √13 m from the charge.
Location ' y ' is √ [ (-3)² + (-2)² ] = √13 m from the charge.
The magnitude of the E-field is the same at both locations.
The direction is also the same at both locations ... it points toward the origin.
Some examples of stable system are:
1) functions of sine
2) DC
3) signum
4) unit step
5) cosine.
Happy Studying! ^^