Answer:
The placement of effort force, resistance force, and fulcrum.
Explanation:
The placement of effort force, resistance force(which is the load to be moved), and fulcrum differentiates between the classes of levers.
Levers are divided into three classes and they are the first class, second class and third class lever. This machines are differentiated from one another depending on the position of their effort(E), Load applied(L) and the fulcrum (L).
For first class lever, the fulcrum is in between the load and the effort e.g a see-saw, scissors etc
For second class lever, the load is in between the fulcrum and the effort e.g a wheel barrow
For third class lever, the effort is in between the fulcrum and the load e.g a stapler
