Home~Introduction To Machines~The Parent Machines~How The Lever Works ~How The Inclined Plane Works ~Quiz As we said before The Lever is one of "The Parents" of all the machines in the world. The Lever is also part of the six simple machines. To be exact, a Lever is basically a rigid bar resting on a pivot or commonly known as a fulcrum which is used to lift heavy or firmly fixed loads with one end when pressure or force is applied to the other end. When using a basic class 1 lever the object moves from the opposite arm that you are putting pressure to. Levers have 3 types of classes. There are class 1 levers, class 2 levers, and class 3 levers.
An example of a class 1 lever is a teeter-totter. The fulcrum or pivot is in the middle of the two arms. The effort arm and the load arm. The class 1 lever can produce a mechanical advantage of 1, below 1, or greater than 1. This all matters on where you place the fulcrum or pivot. If you place the fulcrum closer to the effort (which makes the load arm longer), the mechanical advantage will be less than 1. If you place the fulcrum in the middle of the two (which makes both sides equal length) you will get a mechanical advantage of 1, and finally if you put the fulcrum closer to the load arm (which makes the effort arm longer) the mechanical advantage will be over 1.
An example of a class 2 lever is a wheel barrel. The fulcrum or pivot is on the end of the machine and the load arm is in between the effort arm and the fulcrum or pivot. Since the effort arm is longer than the load arm, the mechanical advantage will always be over 1. And when the mechanical advantage is over one, it means that it is easier to use and it takes less force to lift the load. In this class the effort arm is always longer than the load arm. It is not adjustable.
An example of a class 3 lever is a tweezer. This is where the fulcrum or pivot is also on the end of the machine. But this time, the effort arm is in between the load arm and the fulcrum. This means that the effort arm is shorter then the load arm. This results in a mechanical advantage lower than 1. This is because if the effort arm is shorter than the load arm, the person has to put more force then needed. Even though this is not efficient people use these machines for different things such as sports (hockey stick) or pulling out tiny things from the human body (tweezers). The load arm will always be longer than the effort arm in this class. It is not adjustable. Here is a video on The Lever:
As we said before The Lever is one of "The Parents" of all the machines in the world. The Lever is also part of the six simple machines. To be exact, a Lever is basically a rigid bar resting on a pivot or commonly known as a fulcrum which is used to lift heavy or firmly fixed loads with one end when pressure or force is applied to the other end. When using a basic class 1 lever the object moves from the opposite arm that you are putting pressure to.
Levers have 3 types of classes. There are class 1 levers, class 2 levers, and class 3 levers.
An example of a class 1 lever is a teeter-totter. The fulcrum or pivot is in the middle of the two arms. The effort arm and the load arm. The class 1 lever can produce a mechanical advantage of 1, below 1, or greater than 1. This all matters on where you place the fulcrum or pivot. If you place the fulcrum closer to the effort (which makes the load arm longer), the mechanical advantage will be less than 1. If you place the fulcrum in the middle of the two (which makes both sides equal length) you will get a mechanical advantage of 1, and finally if you put the fulcrum closer to the load arm (which makes the effort arm longer) the mechanical advantage will be over 1.
An example of a class 2 lever is a wheel barrel. The fulcrum or pivot is on the end of the machine and the load arm is in between the effort arm and the fulcrum or pivot. Since the effort arm is longer than the load arm, the mechanical advantage will always be over 1. And when the mechanical advantage is over one, it means that it is easier to use and it takes less force to lift the load. In this class the effort arm is always longer than the load arm. It is not adjustable.
An example of a class 3 lever is a tweezer. This is where the fulcrum or pivot is also on the end of the machine. But this time, the effort arm is in between the load arm and the fulcrum. This means that the effort arm is shorter then the load arm. This results in a mechanical advantage lower than 1. This is because if the effort arm is shorter than the load arm, the person has to put more force then needed. Even though this is not efficient people use these machines for different things such as sports (hockey stick) or pulling out tiny things from the human body (tweezers). The load arm will always be longer than the effort arm in this class. It is not adjustable.
Here is a video on The Lever: