The first class of levers is the most well-known. This class of lever is where the fulcrum is in the middle of the load and the effort. The amount of effort that is needed is determined by where the fulcrum is placed.
If the effort arm is the same length as the load arm (the fulcrum is an equal distance from the load and the effort) then the mechanical advantage is equal to one. This means that the effort you put into the lever and the amount of effort that comes out is about the same. The only difference is caused by the friction on the tip of the fulcrum, which means that a little of your energy goes towards overcoming that friction.
If the effort arm is longer than the load arm (the fulcrum is closer to the load) then there is much less effort needed to lift the load. On this lever the mechanical advantage is greater than one. This is because when the fulcrum is moved over there is a longer distance that you have to move the end of the effort arm in order to lift the load to the desired height. If the load arm is longer than the effort arm (the fulcrum is closer to the effort) than you need a lot more force in order to lift the load. On this lever the mechanical advantage is less than oneThis is because there is a much smaller distance you have to move the effort arm but you have to use more force in order to move the end as far as you need. Some examples of first class levers are the see saw, scissors, the hammer, and the crowbar.
First-Class Levers
The first class of levers is the most well-known. This class of lever is where the fulcrum is in the middle of the load and the effort. The amount of effort that is needed is determined by where the fulcrum is placed.If the effort arm is the same length as the load arm (the fulcrum is an equal distance from the load and the effort) then the mechanical advantage is equal to one. This means that the effort you put into the lever and the amount of effort that comes out is about the same. The only difference is caused by the friction on the tip of the fulcrum, which means that a little of your energy goes towards overcoming that friction.
If the effort arm is longer than the load arm (the fulcrum is closer to the load) then there is much less effort needed to lift the load. On this lever the mechanical advantage is greater than one. This is because when the fulcrum is moved over there is a longer distance that you have to move the end of the effort arm in order to lift the load to the desired height.
If the load arm is longer than the effort arm (the fulcrum is closer to the effort) than you need a lot more force in order to lift the load. On this lever the mechanical advantage is less than oneThis is because there is a much smaller distance you have to move the effort arm but you have to use more force in order to move the end as far as you need.
Some examples of first class levers are the see saw, scissors, the hammer, and the crowbar.
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