Pulley

A pulley is like a magic wheel that helps you lift things up. Imagine you have a heavy bucket you need to lift to the top of a tree. If you try to lift it straight up, it will be really hard because you'll have to use all your muscles. But if you attach a pulley to the top of the tree, you can use a rope to lift the bucket up to the pulley first.

Here's where the magic happens! When you pull the rope down, the pulley at the top helps lift the bucket up with very little effort from you. That's because the pulley has a groove called a "sheave" where the rope fits into. As you pull the rope down, the sheave spins and makes it easier to lift the bucket up.

Some pulleys have one wheel called a "single pulley" and others have two wheels called a "double pulley". Double pulleys make it even easier to lift things because they change the direction of the force you're using. This means you can pull down on the rope and lift the bucket up at the same time.

So, that's how a pulley works. It's a special wheel that helps you lift things up with less effort. Whether you're trying to lift a bucket or pull up a sail on a boat, pulleys are a handy tool to have around!