The Lever
The lever is one of the six simple machines, also one of the most basic of those six machines. The lever usually consists of a rigid arm which is supported on a fulcrum, also known as the pivot point. You apply force on one side of the lever, and move an object on the other side by result. It usually moves the object from the opposite direction than the one you are applying force at.
This is a diagram of a lever. The load (which can also be called the resistance) is the object you are trying to lift, while the effort is the force you apply to move the load. The distance between the load and the fulcrum is known as the resistance arm, or the load arm. The distance between the fulcrum and the effort is called the effort arm.
A very common example of a lever that we are exposed to at an early age is the teeter-totter. One person sits on one side, and another on the other, while the point in the middle is the fulcrum. However, not all levers look like teeter-totters. In fact, there are three different classes of levers, and the teeter-totter is an example of a Class 1 Lever.
In a first class lever, the fulcrum is placed between the load and effort, and can produce an ideal mechanical advantage of either 1, below 1, or above 1. An example of this is a teeter-totter, or even a hammer, as seen in the above diagram.
In a second class lever, the load is between the fulcrum and effort. The load arm is also shorter than the effort arm, and always produces an ideal mechanical advantage of above 1. This is because you have more leverage, and since the ideal mechanical advantage of a lever can be calculated as IMA = effort arm/load arm. The effort arm will always be longer, and thus, a larger number divided by a smaller number will always produce a number above 1.
In a third class lever, the effort is between the fulcrum and load. The effort arm is shorter than the load arm, and always produces an ideal mechanical advantage of below 1. You have less leverage, and it will result in a smaller number being divided by a larger one, producing a number that is always less than one.
It should also be noted that the mechanical advantage of a lever will usually be closer to its ideal mechanical advantage (thus having a higher mechanical efficiency) than an inclined plane. This is because most of the work that is wasted using an inclined plane is NOT wasted in using a lever. The work is wasted overcoming friction, and since the surface area rubbing against each other is considerably less in a lever, the lever is usually closer to its ideal mechanical advantage.
Examples of Levers in Real Life: Baseball bat: The end of the bat being the fulcrum, the area where you place your hand being the effort, and the tip of the bat being the load. The baseball bat is a class three lever.
The lever is one of the six simple machines, also one of the most basic of those six machines. The lever usually consists of a rigid arm which is supported on a fulcrum, also known as the pivot point. You apply force on one side of the lever, and move an object on the other side by result. It usually moves the object from the opposite direction than the one you are applying force at.
This is a diagram of a lever. The load (which can also be called the resistance) is the object you are trying to lift, while the effort is the force you apply to move the load. The distance between the load and the fulcrum is known as the resistance arm, or the load arm. The distance between the fulcrum and the effort is called the effort arm.
A very common example of a lever that we are exposed to at an early age is the teeter-totter. One person sits on one side, and another on the other, while the point in the middle is the fulcrum. However, not all levers look like teeter-totters. In fact, there are three different classes of levers, and the teeter-totter is an example of a Class 1 Lever.
In a first class lever, the fulcrum is placed between the load and effort, and can produce an ideal mechanical advantage of either 1, below 1, or above 1. An example of this is a teeter-totter, or even a hammer, as seen in the above diagram.
In a second class lever, the load is between the fulcrum and effort. The load arm is also shorter than the effort arm, and always produces an ideal mechanical advantage of above 1. This is because you have more leverage, and since the ideal mechanical advantage of a lever can be calculated as IMA = effort arm/load arm. The effort arm will always be longer, and thus, a larger number divided by a smaller number will always produce a number above 1.
In a third class lever, the effort is between the fulcrum and load. The effort arm is shorter than the load arm, and always produces an ideal mechanical advantage of below 1. You have less leverage, and it will result in a smaller number being divided by a larger one, producing a number that is always less than one.
It should also be noted that the mechanical advantage of a lever will usually be closer to its ideal mechanical advantage (thus having a higher mechanical efficiency) than an inclined plane. This is because most of the work that is wasted using an inclined plane is NOT wasted in using a lever. The work is wasted overcoming friction, and since the surface area rubbing against each other is considerably less in a lever, the lever is usually closer to its ideal mechanical advantage.
Examples of Levers in Real Life:
Baseball bat: The end of the bat being the fulcrum, the area where you place your hand being the effort, and the tip of the bat being the load. The baseball bat is a class three lever.
Wheelbarrow: The fuclrum being the wheel, the part where you lift the wheelbarrow being the effort, and the thing you are trying to lift the load.
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