We will discuss here about the simple machine.
Suppose, we have a sealed can full of cookies and when we like to have one from it. We have tried to open the lid of the can with our fingers but failed. We insert the end of the metal spoon handle at the edge of the lid of the can and just apply a little pressure at the spoon head and we can open the lid easily. It happen so easily; because the spoon had worked here as a simple machine.
Machines, as we have the general idea, are used in factory. But there are some simple machines we use daily in our life. These are screw-driver, bottle- opener, sewing machine, scissors etc. Some are inbuilt even in our body- such as jaws, arms, legs, etc. With a machine we perform or do a work or job more quickly and easily than it could have been done by using our hands.
To do some work we need to exert some effort. If the work-load is heavy we have to exert more effort, and in case of light work less effort is to be applied. But there are some tools, which help us to do heavier works by exerting minimum effort. These tools are called machines.
What is machine?
Machine is a device or scheme, which makes a work easier to do. In other words, machine is a device by means of which a lesser force, exerted at one point, helps to overcome another bigger opposing force easily at some other point.
How does a simple machine work?
To open the lid of the cookie can, the spoon acted as a simple machine. In the language of science it is called a lever. The lever is a bar like object, which may be turned or moved freely about a fixed point of support. A lever has three parts
Fulcrum (F): It is a fixed point about which the lever moves or turns
Load arm (L): The arm that extends from the fulcrum to the load point.
Effort arm (E): It is the arm that extends from the fulcrum to the point of application of efforts.
In case of the spoon we can see all three parts of a lever. The point at which the spoon touches the outer edge of the can is the fulcrum (F). Here the load arm (L) is very small, just extending from the fulcrum to the end of the spoon handle that touches the inner edge of the lid. The effort arm (E) is the longest, which is extended from the fulcrum to the spoon head.
Scientists have calculated that, a lever with longer effort arm gives more advantage in comparison to a lever with shorter effort arm.