classes of levers?

Question

What are the differences in classes of levers (third, second, and first class) in terms of effort force, effort resistance, and resistance distance?

Answer 1

1st class: the fulcrum is between the effort and the load; effort force could be either less or more than load.
2nd class: the fulcrum and the effort are at opposite ends with the load in between, so the effort force is less than the load.
3rd class: the fulcrum and the load are at opposite ends with the effort in between, so the effort force is more than the load.
Energy is assumed to be conserved, so a smaller effort force means a greater effort distance and vice versa.
See the wiki ref. below, but ignore what they say in the 3rd-class description about about 1st class being like 2nd class, with effort less than load; it can be either way.