Learn about pulleys with this interactive video lesson on pulleys, for kids.
Learn how simple physics helps make everyday life easier. Make your own pulley system at home. You will need some wire, thread, a spool, a hook and a bucket filled with toys or other materials. After assembling the pulley, first try and lift the bucket with your hands, and then again try lifting it with the pulley. Which one is easier?
Sometimes, it’s not easy to lift heavy objects with only human force. This problem can be fixed with the help of a simple machine like a pulley.
What is a Pulley?
A basic pulley comprises of a wheel on a fixed axle, with a groove along the edges to guide a rope or cable.
Load = the weight of an object
Effort = the amount of force required to lift or move this object.
When you put two or more wheels together, and run a rope around them, you have created a great lifting machine.
As you add more pulleys, you increase your mechanical advantage and it becomes very easy to lift the same load.
The trade-off is that as you increase the number of pulleys, you require a greater amount of rope to achieve the same result. Since you have decreased the effort needed to lift the load, you have to apply the force for a longer period of time.
For instance, it takes more effort to lift the load in a one pulley system. In a three pulley system it takes less effort, and it takes still lesser effort to lift the load in a five pulley system.
Where do you notice a pulley around you? Hint- you use one in a building.
Looking for more physics articles and videos? Go to: Physics for Kids.