What is the major factor controlling how levers work?

Displacement between Fulcrum, Job and Force

Explanation:

The employment and use of levers is simple. Levers reduce the force required to do a task by introducing the concept of moment.

There are there components in a simple lever.

1) The Fulcrum

2) The Job (Load)

3) The Force (Effort)

Typically if it weren't for levers then the three points/components would be at the same point. A lever creates a displacement between all these three components create moment. The higher the displacement between the three the lower the force (effort) required to do the job (lift the load).

mistakes are ok

v=ir = 3x15 =45 v