Pulley is a simple machine and comprises of a wheel on a fixed axle, with a groove along the edges to guide a rope or cable.
Pulleys are used to reduce the time and energy taken to lift heavy objects.
Here, 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.
Understand the mechanism of the simple machine, the pulley. Understand and learn about how these machines make work a lot more easier and less time consuming with the help of this animated learning module for kids.