Define ‘electrostatic potential energy’.

Electrostatic potential energy is the energy that a stationary charged particle has due to its position in an electric field. It is defined as the work done by an external force to bring a charged particle from the reference point to its current location in an electric field, without any acceleration.

Here are the steps to define 'electrostatic potential energy':

1. Understand the basic concept: Electrostatic potential energy is related to the forces between charged objects. Just like gravitational potential energy is the energy an object has because of its position in a gravitational field, electrostatic potential energy is the energy a charged object has because of its position in an electric field.

2. Know the formula: The formula for electrostatic potential energy (U) is U = k * q1 * q2 / r, where k is Coulomb's constant, q1 and q2 are the amounts of charge, and r is the distance between the charges.

3. Understand the factors: The electrostatic potential energy depends on the amount of charge on each object and the distance between them. If the charges are like charges (both positive or both negative), the potential energy is positive, indicating that repulsive work has been done. If the charges are unlike (one positive and one negative), the potential energy is negative, indicating that attractive work has been done.

4. Consider the reference point: The reference point at which the potential energy is defined to be zero is at infinity. This means that as two charges are brought closer together from infinity, work is done on the system if the charges are like charges, and work is done by the system if the charges are unlike.

5. Apply the concept: Electrostatic potential energy is a scalar quantity, not a vector. It is a form of potential energy that can be converted into other types of energy, such as kinetic energy.