Question

What are conservative and non-conservative forces?

Answer 1

Hint: The term conservative gives you a hint that something is being conserved. Which means there is no dissipation associated with this conservative force, while there is dissipation in non-conservative forces.

Complete step by step answer:
We can define conservative forces as forces which act on a body and the mechanical energy associated with the system is conserved. But in actual definition, conservative forces are forces that do work on a body that only depends only on the endpoints and not the path taken. So the work done depends only on the initial point and final point of the path taken by the body. So the work done by a conservative force in a circular path is zero because the initial point and the final points are the same. Electrical force, gravitational force are examples for conservative forces.
Non- conservative forces are forces which act on a body and the work done on the body by the force is dependent on the path followed. During the motion of a body due to non-conservative force, mechanical energy is dissipated, so we can call the non-conservative forces as dissipative courses. The lost energy is not recoverable in most cases. Friction is a good example for non-conservative forces.

Note: A force is called a conservative force if it can be written as the gradient of a scalar potential. For example in the case of Electric field, it can be expressed as the gradient of electrical potential which is a scalar potential.
\[E=-\nabla V\]
E is the electric field
V is the scalar potential.