Examples of first class simple machines?

First-class simple machines include the lever, the pulley, and the seesaw. In a lever, the fulcrum is positioned between the load and the effort, allowing for the lifting of heavy objects with less force. Pulleys also utilize this principle by changing the direction of force, making it easier to lift loads. Seesaws function similarly, with a fulcrum in the center that allows two people to lift each other by shifting their weight.