Pulleys: Applications and Uses
A simple system that has revolutionized the way the human world works is the pulley system. There are after all easier ways to do everything and science has empowered us. How is that? For one, human beings are no longer lifting larger weights off the ground and in the near future, we might be even sending postcards to our friends on another planet.
The one thing which has already happened is the invention of pulley system. It has made life easier as we no longer need to strain our backs to lift off a load. And a strong man can easily lift a lot of weight, but a smart man will use a pulley.
What is a Pulley?
A pulley is a simple machine that uses a wheel and rope to lift off heavy weight objects and move them around. The simple machine can either consist of one wheel or more. The pulley system helps in lifting really heavy objects as it multiplies the force that is one need to apply to lift the weight, making the task easier.
Applications of Pulleys in simple set-ups
The one obvious place that comes to everyone’s mind when asked about the application and use of pulleys is a crane and the sailboat. But, there are easier set-ups to where pulleys are used and we hardly pay attention. The blinds of a curtain are moved with the help of a pulley.
The use of a pulley to take out water from a well is one application that almost everyone has seen in their life. There are other set-ups where pulleys are used but these are not visible to us directly as they are a part of a bigger machine or mechanism. Pulleys are also used in vehicles to ensure that the parts of the vehicle work smoothly.
The mechanism of a working pulley
One of the simplest types of pulley that can be explained is the pulley that has only one wheel. The end of the rope that has a weight attached to it is lifted up only when an equal amount of force is applied from the other end, either manually or mechanically.
If a weight of 100 Kg is attached to one end of the rope, then a force that is equal to 100 Kg needs to be applied on the other.
But, this set-up is not helping as the force applied is the same amount as the weight that needs to be lifted. This is why more wheels are added to the set-up to ensure that the force applied is less than the weight that needs to be lifted. In the set-up described above, if one more pulley is added to the set-up, then the force required to lift off the 100 Kg weight reduces by half and only 50 Kg of force is required.
So, keep on adding more wheels to the pulley set-up and you are lowering down the force that needs to be applied to lift off the weight. This is how a conventional and simple machine like a pulley is making life easier for us.
Uses of Pulleys
There are innumerable uses of pulleys. Some of the most common ones are:
- A pulley system is used in an elevator to pull the weight of 5 people against gravity.
- A gym is one place where one can find a lot of machines using the pulley system.
- Flagpoles on a sailboat or a ship used a pulley system to hoist a flag or bring it down.
- Pulley systems are used in industrial machines across different applications from production floor to delivery room.
There’s a catch to this brilliant machine. You use less force with a pulley, but you must pull more because energy is wasted due to friction; when the rope rubs against the pulley wheels. Nonetheless, it feels simpler and effortless to use a pulley, now that’s an important thought, isn’t it?