A conservative force is a type of force that, when applied to an object, does not depend on the path taken by the object. This means that the work done by the force is independent of the path and only depends on the starting and ending positions of the object.
An example of a conservative force is gravity. Regardless of the path taken by an object, the work done by gravity is only dependent on the starting and ending positions of the object. This is why the potential energy due to gravity is defined as -mgh, where m is the mass of the object, g is the acceleration due to gravity, and h is the height of the object above the ground.
A non-conservative force is a type of force that, when applied to an object, depends on the path taken by the object. This means that the work done by the force is not independent of the path and can vary depending on the path taken by the object.
An example of a non-conservative force is friction. The work done by friction depends on the distance traveled by an object, which means that the path taken by the object affects the work done by friction. This is why the work-energy theorem states that the work done by non-conservative forces, such as friction, decreases the total mechanical energy of an object.
Conservative forces do not change an object's total mechanical energy, as they only transfer energy between potential and kinetic forms. Non-conservative forces, on the other hand, decrease an object's total mechanical energy as they transfer energy to other forms, such as heat or sound. This is why objects eventually come to a stop due to the presence of non-conservative forces like friction.