Explore the structure and principles of the three classes of levers
A lever is a simple machine consisting of a fulcrum, an effort arm, and a resistance arm. Levers can be divided into three classes based on the relative positions of these three components.
When a lever is balanced, the product of the effort and its arm equals the product of the resistance and its arm. Changing any of these quantities will disrupt the balance, causing the lever to rotate.
The fulcrum is located between the effort and resistance points. Examples: seesaw, balance scale, scissors.
Characteristics: Can change the direction of force. When effort arm equals resistance arm, it neither multiplies force nor increases distance.