Compare and contrast the three
classes of levers.

Class I . . .
The fulcrum is between the effort and the load.
The mechanical advantage may be any positive number, more or less than ' 1 '.

Class II . . .
The load is between the fulcrum and the effort.
The mechanical advantage is always greater than ' 1 '.

Class III . . .
The effort is between the fulcrum and the load.
The mechanical advantage is always less than ' 1 '.