Levers
Definition
Lever
A rigid bar that pivots on a fulcrum to move a load with an applied effort.
Types of Levers
Levers are classified into three types based on the relative positions of the Load (L), Effort (E), and Fulcrum (F).
- First-Class Levers
- Second-Class Levers
- Third-Class Levers
First-Class Levers
Definition
1st-class lever
A lever where the fulcrum is between the effort and the load. For example, a seesaw or a pair of scissors.
- Can increase force or change the direction of force.
- The mechanical advantage depends on the distance between the fulcrum and the effort/load.
- Seesaw: The fulcrum is in the center, with the effort and load on opposite ends.
- Crowbar: Used to lift heavy objects by applying force on one end.
Second-Class Levers
Definition
2nd-class lever
A lever where the load is between the effort and the fulcrum. For example, a wheelbarrow.
- Always provide a mechanical advantage (effort is less than the load).
- The effort moves a greater distance than the load.
