All levers fall into one of three types of lever. How can we tell which lever is in which class?
Well, a first-class lever is a stick where the fulcrum is in between the weight and the energy moving the weight (your hands, for example). Some common first-class levers are see-saws, crowbars, and pliers. A pair of scissors scissors (which use two first-class levers together), and a hammer pulling a nail are also first class levers.
And then a second-class lever is a stick where the fulcrum is at one end of the stick and you push on the other end. The weight is in the middle of the stick. Some common second-class levers are doors, staplers, wheelbarrows, and can openers.
And then a third-class lever is a stick where the fulcrum is at one end of the stick, you push on the middle, and the weight is at the other end of the stick. With a third-class lever, you have to put in more energy than you would just lifting the weight, but you get the weight to move a longer distance in return. Some common examples are a broom, a hoe, a fishing rod, a baseball bat, and our own human arms.
Learn by doing: Find examples of each kind of lever that aren’t mentioned here
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