Question

what is a commutator? what is its importance in classical mechanics?

Answer 1

Do you mean the commutator in electric machines:
http://en.wikipedia.org/wiki/Commutator_%28electric%29

Answer 2

a device that reverses the direction of flow of current through a circuit is called as a commutator.in electric motors,the split ring acts as a commutator.

Answer 3

sry .. i need the answer about commutator operator in calssical mechanics

Answer 4

That sounds as something not used any more. When a mechanical computer information-fed by a perforated paper rolls or flash cards sensed the holes along the paper with small prongs, the small movements from the prongs activated a pre-design mechanical paths to add, subtract, multiply or divide the data input. Such stuff was outdated by the invention of electrical systems (vacuum tube computers).