In order to lift the heavy weights you would often understand that the mechanism which is used in the industries is not to just lift those weights normally but rather to use a scientific mechanism known as pulley to pick those weights.
Pulley significantly reduces the effort which is required to lift the load due to the load sharing mechanism and due to the way in which the effort is applied to lift the load.
Another reason why pulley system is often used is because it can easily be scaled for lifting heavier loads by adding more pulley’s into the system which would still provide you with significant reduction in the overall effort required to lift the load or displace it.
The mechanism works pretty well but it surprisingly simple to understand as well.
We would be explaining it in detail below.
Basics of a pulley:
A pulley consist of a single wheel or a mechanism of wheels which are arranged in such a manner that when a rope is passed what these wheels and you use the rope to pick things less amount of effort is required to pick those things as compared to the entire weight of that particular thing.
If you use normal labour to pick those weights there is a limit to which you can keep on adding the labour to pick those weights. Besides after a while the manual method becomes in-efficient due to the amount of resources which are required.
Beyond a certain point it is not easily possible to keep on adding labour to pick those weights and that is where machines like a pulley comes in.
It reduces the effort which is required to pick up those weight with the help of the wheels and the gears. This machine is categorised as a simple machine.
Working off a pulley:
One wheel pulley:
As the name suggests this pulley consist of only a single wheel and the rope is around that particular wheel. On one end the weight which is to be lifted as tied and on the other end the effort which is required to lift that particular weight is applied. To give you an example of the amount of effort which is required to pull that particular weight, let say you had to lift a load of 100 kg then for that you would have to pull the lows and of the rope for about 1 m.
Two wheel pulley:
In this type of pulley there are two wheels and the rope is worn around two wheels and that is where the amount of force which is required to pick a weight of 100 kg is equivalent to 50 kg and not 100 kg and that is where the amount of force which is required to pick such a weight is half as compared to the one wheel pulley. This provides us with a mechanical advantage because you had to use a less forced to pick the same amount of weight and therefore as the number of wheels actually increase the amount of force which is required to pick the same quantity of weight reduces.
Mechanical advantage is the measure of how much advantage the machine provides to us in terms of multiplying the force which we are applying. If the machine is having more mechanical advantage like in the case of a pulley if the machine is having more wheels than more mechanical advantage would be provided and less force would be needed to pick the same amount of weight. If you look at the amount of distance for which we have moved the rope it would be double of the earlier distance which we had more and therefore if for example you have to move the bed were 1 m then you would have to the rope by at least 2 m.
Four wheel pulley:
As we have explained of war with the increase in the number of is the amount of force which is required to pull the same amount of weight is actually reduced and therefore if you use a four wheel pulley then you would need a force which is equivalent of only 25 kg to pull up a weight of 100 kg. With that being said now you would have to pull the rope for 4 meter. The mechanical advantage which we have enough or wheel pulley is of four.
Comparing pulley with a lever:
From the above three examples of a pulley you would understand that a pulley magnifies the amount of force which is used to lift something. The same principle can be used by a lever as well.In a lever the distance at which you put the weight from the fulcrum that is the balancing point of the liver determines the mechanical advantage which you have and therefore it all depends on the weight which you want to pick.
What is the secret?
Many of the people ask is that there is clearly some trip to the working of the pulley because to lift the weight of 100 kg there would always be a force which is required of 100 kg and therefore if the force required is equivalent to 25 kg then what is the secret year. The secret here is that even though the amount of force which is required at the same instance of is on the lower side but you had to pull the rope for the distance which is multiplied by the mechanical advantage to the distance which you had required to move the rope if there was no mechanical advantage. That means that enough or wheel pulley you would have to pull the rope for 4 meter instead of just 1 m when you want to take the weight by 1 m.
The only advantage here is that at a single instance of time the amount of force which you need to pick up the weight would be divided by the mechanical advantage which you have and therefore the entire task of picking up that weight actually seems much more easier than if you you were to pick that weight with the equivalent amount of force.
Simple machines can be of plenty of different eyes but in most of the cases they are actually used to reduce the amount of effort which is required to recover certain weight.
When you’re speaking about pullies the pullies can be built according to the range of the weights which they have to lift and therefore you can easily get a wide range of police to choose from depending on the weight which you want to pick. These pullies need to be very well maintained in case you are lifting very heavy amount of weights and therefore you how to always look after the maintenance as well as the oiling of these pullies to ensure that there is proper lubrication for the rope which is being used to pick up the weight.