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Lever |
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A lever is a rod or bar that is used to lift or move a load. Levers also open things. A lever is usually a rigid bar that turns around a fulcrum. (A fulcrum is the point around which a lever turns and is supported.) A crowbar is one example of a lever that helps lift heavy objects. A seesaw is another example of a lever. Do you have a pair of pliers at your house? Then you have a lever. A pair of pliers is made of two levers. They are connected at a fulcrum. You can squeeze these two levers together to create force to help you turn a screw or do other work. Have you ever opened a can of paint? You probably used a lever of some kind to pry the lid open. Bottle openers are levers, too. It would be almost impossible to get a top off of some bottles without these handy levers!
Do you have a suitcase that rolls on wheels? That suitcase has several simple machines. One of them is the long handle. The handle is a kind of lever that helps balance the suitcase so it can be pushed easily. Do you have a hammer at home? The claw end of it is a lever! Using that end, you can easily pull nails out of wood. The hammer makes the work much easier.
Nutcrackers are special levers that help open the hard shells of different nuts. You certainly can’t crack these with just your fingers. Have you ever trimmed limbs or branches off of trees? Have you had to help cut fence wire? Did you use special cutters to do it? The handles of those cutters are levers. They help you have enough force to cut the wood or wire.
Have you been fishing? A fishing rod is a lever! The rod helps you have enough force to lift the fish from the water. Your hand works as a pivot to raise and lower the lever (the fishing rod). To learn more about levers, visit this site: http://www.factmonster.com/ce6/sci/A0829558.html
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