What Are Machines 

There are many tasks that we cannot do ourselves, or we may need to put in a lot of time and effort to do them. To do such tasks, we use machines.

• A machine in the broad sense of the word is any device designed to translate some form of energy into useful work.

Why we need Machines

•  A machine is a tool that makes our work easier
• . It helps us to overcome a larger force (required to move a load) by applying a lesser force (called effort).
•  Machines can be simple or complex. 

Simple Machines

A simple machine uses a single applied force to get the work done.

•  A “simple” machine is one where both the input energy and the output energy are mechanical in nature .
•  A simple machine has very few parts. 
• A wheelbarrow is an example of a simple machine

Types of Simple Machines

There are mainly 6 types of simple machines.

•  A lever

• Pulley

• Wheel and axle

• Wedge

• Screw

• An inclined plane are some simple machines.

Lever

A lever is a simple machine consisting of a rigid rod which is capable of turning around a pivot called a fulcrum.

 It has three parts, namely, effort, load and fulcrum.

• Fulcrum: The rod of the lever rests on it and the lever rotates about it.
• Load: The weight lifted by the liver is called the load.
• Effort: The force applied on the other end of the rod to lift the load is called the effort. READ MORE…..

Also Check – Class 5 Force Work and Energy – Notes

Pulley

Simple Pulley 

 A pulley is a simple machine used to lift heavy objects.

•  A pulley consists of a wheel with a grooved rim and a rope, chain, or belt wound around it.
•  The wheel rotates around an axle. 

Example: The Garage door is an example of pulley. 

Types Of pulleys

Pulleys are of the following two types:

 Fixed pulley

•  This type of pulley has a fixed axle.
•  A fixed pulley makes work easier by changing the direction of the force.
•  This type of pulley is used to draw a bucket of water from a well. 

Movable pulley 

• This type of a pulley has a free or movable axle.
•  It is used along with a fixed pulley.
•  For example, a crane uses both fixed and movable pulleys to lift heavy loads.  READ MORE

Wheel And Axle

 A wheel and axle is a simple machine made up of a wheel rigidly attached to a  rod (called an axle).

When one rotates the wheel, the axle also rotates. 

Example Of Wheel And Axle

 A steering wheel and a doorknob are examples of wheel and axle. READ MORE…

Inclined Plane

• An inclined plane is a tilted surface or a slope 
• An inclined plane is  used to move a heavy load with less effort.

Example: Ramps in hospitals and slides on the playground are examples of inclined planes. READ MORE…..

Screw

• It is a kind of simple machine in which nail with grooves cut on it.
•  A screw is a modified inclined plane
• It has a groove at its head into which the tip of a screwdriver fits easily.
•  It is used to hold things tightly together. Screws are used in objects such as light bulbs. READ MORE…

Wedge

•  A wedge is a simple machine that has a long triangular shape with one broad or blunt end, and one sharp end. 
• The sharp end is used to cut or slice objects.
•  A wedge may also be formed when two inclined planes are joined together.

Examples: The head of an axe and the blade of a knife are examples of a wedge. READ MORE…