Since the dawn of Civilization, mankind has looked for ways and means to make work easier for him. His eternal quest in this direction has led him to invent Machines of various kinds. What are machines, you may ask. Machines are devices that do work. Machines make our work easier because they magnify the force we apply to them, thus saving our energy and time in getting the job done.
Machines come in many shapes, sizes, and forms. Some machines are very simple, such as a spade, while others are very complex, such as a space rocket.
Machines are of two kinds- Simple Machines and Complex Machines. Let us understand the physics behind simple machines.
A simple machine is a tool or device with a single or couple of moving parts, designed to help us do work. Simple machines have been in use since time immemorial. Prehistoric man used simple machines to chop, lift, push and pull things. Simple machines helped him to chop firewood, build shelters, make simple floating rafts with oars and carry loads from one place to another.
Simple machines are all around us. The cork-screw used to remove corks, see-saws, scissors and nail-clippers, spade used for digging, axe to chop wood, inclined aisle used for wheelchairs, and even a knife, are all examples of simple machines prevalent in daily use.
Simple machines form the fundamental unit- the building blocks- for the making of complex machines. Complex machines are a motorised, intricate assembly of a number of simple machines working together in perfect tandem.
What Can Simple Machines Do-
Simple machines cannot work by themselves. They need input in the form of applied force or effort by a person or animal (in the case of animal carts). They can increase the magnitude of the force of a pull or push applied by a person, magnify the effort applied, change the distance (increase or decrease) and change the direction in which movement is taking place. Simple machines do the following-
- transfer a force from one place to another
- change the direction of a force
- increase the magnitude of a force
- increase the distance or speed of a force
It is important to note that simple machines work only when manoeuvred manually.
Types Of Simple Machines-
Simple machines are divided into the following six types-
- Wheel and axle
- Inclined plane
All six simple machines have been used for thousands of years. The science behind several of them such as lever, pulley and screw were explained in lucid terms by the scientist Archimedes in 3rd Century BC. He discovered the principle of mechanical advantage in simple machines, laying the ground for further research and inventions based on these principles. This is what Archimedes had to say about the lever-
“Give me a lever and a place to stand, and I’ll move the world.”
These words pretty much sum up the potency of simple machines in magnifying applied force and the power of mechanical advantage.