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In the olden days, people work hard to achieve a simple task. As time passed by, they learned to construct specific machines with low moving parts to accomplish their required task. These machines are known as simple machines.
Understanding how to use different types of levers could make a significant difference in selecting and using them. This article will look at the different types of levers and how you can use them to your advantage.
What is a Simple Machine?
A mechanical device that changes its motion or position or magnitude by the moment of few parts or no parts to achieve the required task is known as a simple machine. There are six types of simple machines and a lever is one of them.
What is a Lever?
Levers are machines used to increase force. We call them “simple machines” because they have only two parts — the handle and the fulcrum. The handle or bar of the lever is called the “arm” — it’s the part that you push or pull on. The “fulcrum” is the point on which the lever turns or balances.
Terms Associated With A Lever
Load: A resistive force that is to be overcome by a machine. Its S.I. unit is Newton.
Effort: It is an external force applied to a simple machine to overcome a load. Its SI unit is Newton.
Fulcrum (Pivot): The point on which something turns or is supported.
Mechanical Advantage: The ratio of load (L) to Effort (E).
How Does a Lever Increase The Force?
Levers do not create energy. Levers convert a small force applied over a long distance to a large force applied over a small distance. Work is the force times the distance, W = Fd, so the total work done is the same with or without the lever.
Look closely at a lever as you use it. The end that lifts the object moves a very small distance d as the job is carried out, but the end of the lever that your hand is pushing on moves a large distance as the job is carried out. Because the total work done must be constant, and work is force times distance, the force must go up if the distance goes down.
The lever converts the little force of your hand at one end to a large force at the other end; large enough to do a big job. But it does this at the cost of a larger distance. You must therefore push on one end of the lever for a longer time than you would have to without the lever.
According to the work-energy theorem, the amount of work you do on a system becomes the energy contained in the system. Because the work is constant with or without the lever, the energy is also constant. A lever, therefore, does not create energy. The energy inputted to do a certain job is exactly the same with or without the lever. The lever just maximizes efficiency.
All simple machines – levers, pulleys, ramps, screws, gears, etc – operate on this same principle. They increase efficiency by allowing a high-force/small-distance job to be accomplished by humans who operate best in low-force/large-distance mode. But the total work and total energy expended for a given job is always the same, no matter what machine you use.
Types of Lever
There are 3 types of levers classified on the basis of relative positions of fulcrum, effort, and load. These three types of levers are:
1. 3 Types of Levers – First Class Lever
The fulcrum of a first-rate lever is located between the force and the load. To summarize, the effort travels a long distance with a first-class lever to move the weight a short distance, and the fulcrum is located between the action and the load.
The fulcrum is located between effort and resistance. The effort is applied on one side of the fulcrum while the load is placed on the other. A lead, a crowbar, or a pair of scissors, for example. The mechanical benefit might be less or more than one.
Examples of first class levers are our hand pushing an item, a wheel, and an axle, or pulling a nail out of a wooden board.
2. 3 Types of Levers – Second Class Lever
The load in second-class levers is located between the effort and the fulcrum. A wheelbarrow is a classic example. The effort goes a long distance to raise a heavyweight, with the axle and wheel acting as the fulcrum. The effort is distributed across a broad area in a second-class lever to raise the weight a short distance.
In the second-class lever, the length of the effort arm extends to the fulcrum and always surpasses the size of the load arm.
Examples of second class levers are wheelbarrows, crowbars, nutcrackers, bottle openers, car brake pedals, and clippers for nails.
3. 3 Types of Levers – Third Class Lever
The effort in third-class levers lies between the load and the fulcrum, as in barbeque tongs. In third-class levers, the length of the load arm extends to the fulcrum and always surpasses the size of the effort arm. Third-class levers are also loaded in the same direction as the effort.
Examples of third class levers are tweezers, staplers, mousetraps, hockey sticks, and brooms.
| Type of Lever | Mechanical Advantage | Attribute |
| First Class | Greater than 1 | Force multiplier |
| Second Class | Less than 1 | Speed multiplier |
| Third Class | Equal to 1 | Change in the direction of the effort |
Types of Levers Examples
We use levers in our daily life. Following are some of the common examples of levers.
1. Types of Levers Examples – Hammer Claws
Hammer claws are common levers that help you remove embedded nails in wood or other hard surfaces. Hammer claws are first-class levers because the fulcrum is at the base of the hammerhead, and you use effort, also known as force, to lift the handle and pry materials with the metal-claw end.
A first-class lever is similar to a traditional see-saw because the applied force at one end raises the other end, thanks to the fulcrum creating a pivot point in the middle.
2. Types of Levers Examples – Wheelbarrows
Wheelbarrows are helpful everyday tools because they allow you to transport loads that are too bulky or heavy to carry with your arms. A wheelbarrow is a second-class lever because the front wheel serves as the fulcrum. The weight-bearing load rests in the center of the wheelbarrow, and you use human force to lift the handles on the other end to roll the wheelbarrow where you want it to go.
3. Types of Levers Examples – Bottle Opener
A bottle opener is a second-class lever because the pivot point is at one end of the opener and the load is in the middle. In this case, the load is the bottle itself, or specifically the secured bottle cap on the bottle, and the handle provides a way to lift and remove the cap from its tightly secured position. Because applied force is sometimes greater than the strength of the metal cap, the cap might crease or bend in half.
4. Types of Levers Examples – Tweezers and Tongs
Tweezers and tongs are examples of levers that make it easy to lift or remove items, even though the items aren’t heavy. Tweezers and tongs are third-class levers because the fulcrum is at one end and the load is at the other. You must use human effort in the center of the lever to pinch the tweezers or tongs to grasp and lift or remove materials.
5. Types of Levers Examples – Scissors and Shears
Scissors and shears are first-class levers, even though the fulcrum is slightly off-center. The centralized fulcrum still serves as the pivot point that allows you to raise and lower the dual bars at one end with the handles on the other end. Scissors are an example of a lever that uses force to cut or separate materials.
Practice Problems
- What is a Lever?
- How many types of levers are there?
- Explain the positions of fulcrum, load, and effort in
- first class lever
- second class lever
- third class lever
FAQs
What is a lever simple definition?
A lever is a simple machine made of a rigid beam and a fulcrum. The effort (input force) and load (output force) are applied to either end of the beam. The fulcrum is the point on which the beam pivots. When an effort is applied to one end of the lever, a load is applied at the other end of the lever.
What is a lever and its function?
A lever is a rigid rod (usually a length of bone) that turns about a pivot (usually a joint). Levers can be used so that a small force can move a much bigger force. This is called mechanical advantage. Mechanical advantage. Levers can be used so that a small force can move a much bigger force.
What are the main parts of a lever?
The five major parts of a lever are:
Effort
Effort arm
Load
Load arm
Fulcrum
Conclusion
The world of levers can be confusing for many people. With so many different types to choose from, it can be hard to know which one to buy for your particular job. We hope that this article has been helpful in clearing up some of the confusion!
