Levers and their Uses: Description, Types, Examples and Real-Life Applications

A lever is one of the most important simple machines in physics. It helps us perform heavy tasks with less effort by using a rigid bar and a pivot point called the fulcrum. From scissors and pliers to wheelbarrows and human arms, levers are everywhere in our daily lives.

In this concept page, students will understand what a lever is, its parts, types, and real-life applications. They will also learn about pulleys as another important simple machine and how these machines make work easier.

Table of Contents

• What Is a Lever and the Parts of a Lever
• Pulleys and Types of Pulleys
• Did You Know?

What Is a Lever and the Parts of a Lever

Levers are fundamental and simple machines. They are used to working with minimal effort. Every machine is an example of a lever in some form or the other.

Let’s first try to understand how this happens in daily life. When you open a bottle cap using an opener, you are using a lever without even noticing it.

Different Parts of a Lever

A lever has three parts: the fulcrum, the location where the effort is given, and the location where the load is put.
The fulcrum is called the pivot point. In short, we can say that a lever is a rigid bar with a pivot point.

Classification of Levers

In our daily life, we use many tools that make work easier with less effort. Most of these tools work on the principle of a lever. Depending on where the fulcrum (pivot point), effort, and load are placed, levers are divided into different types. Understanding this classification helps us see how simple machines reduce effort and make difficult tasks easier. 

Levers can be classified into, 

• Class one/First-class levers.
• Class two/Second-class levers.
• Class three/Third-class levers.

Now, let's discuss them in detail.

Class one/First-class Levers

First-class levers have a fulcrum (pivot) in the middle. The force is applied at one end, and the weight is located at the other end.

The force is applied in one direction in first-class levers, and the load moves in the opposite direction.

The length of the effort arm where the force is applied can be greater, equal, or less than the length of the load arm.

Real-Life Examples of First-Class Lever

First-class levers are widely used in everyday tools where the fulcrum is placed between the effort and the load. This arrangement helps change the direction of force and makes work easier in different ways depending on the position of the fulcrum.

Some common real-life examples include pliers, scissors, crowbar, seesaw, weighing balance, claw hammer, spoon, and tubewell.

Pliers	Scissors	Crowbar
Seesaw	Wheel and axle	Weighing balance
Claw and hammer	Spoon	Tubewell

How Does a First-Class Lever Work?

Have you ever tried to open the lid of a can with a screwdriver? When you do that, you have to put more effort into the screwdriver's handle at a greater distance than on the load.

In this case, the rim of the can be considered the fulcrum situated between the effort and the load. Here, the lid is the load that is nearer to the fulcrum.

Since the effort arm is greater than the load arm, we can generate a large force on the load and open the lid.

Class Two/Second-Class Levers

Second-class levers have a pivot point (fulcrum) at one side, and effort is put on the other side. The force is applied at one end of the lever, and the weight is located in the middle.

In class two levers, the movement of the force and the load are in the same direction. The length of the effort arm is always greater than the length of the load arm.

 Real-Life Examples of a Second-Class Lever

Second-class levers are commonly used in tools where a heavy load needs to be lifted with less effort. In these levers, the load is placed between the fulcrum and the effort, making work easier.

Some real-life examples include a wheelbarrow, a hole puncher, a bottle opener, a nutcracker, a nail clipper, and an oar.

Wheelbarrow	Hole puncher	Bottle opener
Nutcracker	Nail clipper	Oar

How Does a Second-Class Lever Work?

A classic example of a second-class lever is a wheelbarrow. Wheelbarrows are used to lift heavy loads and cross a large distance carrying that load.

In the case of a wheelbarrow, the fulcrum is located on the axle and the wheel. The effort can move a large distance to lift a heavy load.

 

 Another example of a second-class lever is a bottle opener. The effort arm of the bottle opener is greater than the load arm. Both the effort and the load work in the same direction. 

The pivot point or fulcrum is located at the end, which opens the bottle cap. With minimal effort, maximum force can be created with the effort arm as it is the largest arm to open the corks and the bottle caps.

Class Three/ Third-Class Levers

In third-class levers, the effort is located between the load and the fulcrum (pivot). In these levers, the distance moved by the load is always greater than the distance moved by the effort.

To make these levers work, one must apply a massive force to the load. All kinds of third-class levers have a mechanical disadvantage.

In the case of third-class levers, the input force or the effort is greater than the force produced on the load.

In a third-class lever, the load and the effort always move in the same direction. In all class three levers, the length of the load arm is always greater than the length of the effort arm.

 Real-Life Examples of Third-Class Levers

Fishing rod	Broom	Bow and arrow
Baseball bat	Tweezers	Spade

How Does a Third-Class Lever Work?

The human arm is an example of a third-class lever. When we lift anything using the forearm, we use a class three lever.

In the case of a human arm, the elbow is considered the fulcrum. The load is on the hand, and the effort is located between the elbow and the load.

Pulleys and Types of Pulleys

A pulley is a simple machine. It is used to lift heavy objects. A pulley consists of a wheel that has a grooved track for the rope, chain, or belt to move through it.

When a force is applied at one side of the rope, the belt, or the chain, it uses the pulley system and moves in a different direction.

Pulleys can be of two types,

• Fixed pulleys

• Movable pulleys

Fixed Pulleys

The pulley remains attached to a fixed position with a rope on it in the fixed pulley system.

These pulleys rotate on their axis at a fixed place. The fixed pulleys change the direction of effort. 

Real-Life Examples of Fixed Pulleys

Fixed pulleys are used in many everyday situations where we need to change the direction of force. Common examples include flag poles and sail masts, where the pulley helps lift objects upward more easily by changing the direction of the applied effort. 

Movable Pulleys

Movable pulleys do not remain attached to a rigid support. These pulleys are free to move up and down. 

Movable pulleys remain attached to other objects with the same rope.

Real Life Examples of Movable Pulleys

Movable pulleys are commonly used in heavy lifting machines to reduce effort. We can see them in construction cranes and elevators, where they help lift heavy loads easily by sharing the weight and making the work simpler.