Conservation Physics online classes

conservative and non conservative force:-
conservative forces:-
1) A force is said to be conservative if work done by force does not depend on the path followed by the particle.
2) it depends only on initial and final position of the particle.
3) work done by conservative force along a closed path is equal to zero.
4) Potential energy is only defined for conservative forces ( why, think )
5) some example of conservative forces are gravitational force, electrostatic force, spring force, magnetic force acting between the poles of the magnets.

Non conservative forces:-
1) A force is said to be non conservative if work done by the force depends on the path followed by the particle .
2) work done by non conservative force along a closed path is not equal to zero.
3) work done by non conservative force does not depend on the initial and final position of the particle.
4) Potential energy can not be defined for non conservative forces.
5) some examples of non conservative are friction , air resistance .
6) all the velocity dependent forces are the examples of the non conservative forces.

important points regarding friction
1) when the net force along the contact surface( excluding friction) acting on the body is more than limiting friction value then there will be relative motion between the contact surface and type of friction acting between the contact surfaces would be kinetic.

2) when the net force along the contact surface( excluding friction) acting on the body is less than limiting friction value then there will not be relative motion between the contact surface and type of friction acting between the contact surfaces would be static.

kinetic friction:-
1)friction acting between the contact surfaces when there is relative motion between the same is called kinetic friction.
2) magnitude of kinetic friction between two surfaces is directly propostional to the normal reaction acting between the same contact surfaces.
3) direction of kinetic friction acting on a contact surface A due to contact surface B would be opposite to the velocity of contact surface A with respect to the contact surface B. and vice versa is true as well .