Levers use mechanical advantage to ease lifting; they consist of a bar and a pivot (fulcrum) with effort, fulcrum, and load arranged differently in first, second, and third class levers ...

Class 1 Levers. Class 1 is perhaps the most familiar. Examples of that are a seesaw, a crowbar as well as any time you’ve picked up a stick and placed it on a handy pivot point to lift something ...

Background Seesaws and scissors belong to a certain class of levers, called class 1. Class 1 levers usually have a beam that is rigid, long and thin, like a ruler.