We use different types of devices in our daily life to make our work easier. For example, we need a spade to dig, a broom to sweep, a hammer to pass a nail on the wall and a plank to load up to a height.
we use all these simple things or devices to make our work easier, faster, and convenient. The devices like, spade, nail cutter, knife, etc that we use in our daily life, is simple machine.
Thus, a simple machine is defined as a device, which is used in our daily life to make our work easier and convenient.
Application/use of simple machine
The simple machine makes our work easier faster and convenient in the following some ways,
1. They transfer force from one point to another point.
when we use a knife to open up the lid of a can we apply the effort at the handgrip and it transfers to the noke of the knife.
2. They accelerate the rate of doing work.
For example, when one part of a dhiki is pushed for less distance, the other part of it is lifted for a more distance.
Thus, it increases the rate of doing work.
3. They multiply force i.e. more load is lifted up by applying less effort.
For example, we can turn heavy stone with a crowbar by applying less effort.
4. They change the direction of a force.
For example, in pulleys, when an effort is applied downwards at one end of the string, the load is lifted upwards.
Types of simple machine
Simple machines are of six types,
3. Wheel and axle
4. Inclined plane
Give me a point for a fulcrum, I will turn the earth. This statement is of Archimedes who discovered the lever in 240 BC. The statement tells how efficient a lever is
A lever is a rigid bar, straight or bent, which is able to rotate about a fixed point called fulcrum or pivot.
The distance between the load and the fulcrum is load distance and the distance between the effort and fulcrum is effort distance. Out of all the simple machines, the only lever can show all the properties of a simple machine.
On the basis of the location of effort, load and fulcrum on a lever, it is classified into three types. i.e, First, second and third-class lever.
First class levers are those levers in which the fulcrum is situated at any point between the load and the effort.
This type of lever points all the properties of simple machines. They change the direction of force, multiply force and accelerate the rate of doing work.
When the fulcrum is close to the load, effort distance increases and it multiplies the force. When the fulcrum is close to the effort, load distance increases that is work accelerates. Crowbar, see-saw, dhiki, pliers, scissors and tinsnips are some examples of this kind of lever.
Second class lever
Those levers in which load is at any point between the effort and the fulcrum are second class levers.
They can’t change the direction of the force and are unable to accelerate work because load distance is never greater than effort distance in them. They help us by multiplying the force i.e. MA is always great than one in such a lever.
Nutcracker, Wheelbarrow, bottle opener, the oar of a rowboat, opening, and closing of the door, etc. are the examples of a second class lever.
Third class lever
Those levers which have effort at any point between the load and fulcrum are third class levers.
They are unable to multiply force and change the direction of the force but they help us by accelerating work.
As they have the effort distance always lesser than the load distance the value of MA in them is always lesser than one. Brooms, shovels, sugar tongs, fire tongs, forceps, fishing rods, and hammers are some examples of this type of lever.
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