LEVER

Think of a fishing pole —a very FUN third class lever!

Here you put force on the lever between the fulcrum and the load.

The fish is the load, the fishing rod is the lever, and the handle of the fishing rod is the fulcrum. You are putting FORCE in between the handle and the fish as youPULL your catch out of the water.

A broom is also a third class lever. The fulcrum is your hand on the top of the broom and the load is the dirt on the floor. You put FORCE in the middle of the broom.

You know where else you can find levers?

In your own body!

Your arms work as levers.

When you LIFT an object and carry it in your hand, you are using your arm as a lever.

How about your feet?

Sure!

Try this . . .

Stand up and RAISE YOURSELF up on your TIPTOES a few times. You’ve just used your feet as levers. The load is your body weight, your muscles are doing the work, and your toe joints are the fulcrum.

Who was the first person to use a lever?

Early humans used pieces of wood and long stones as levers as they figured how to till soil and grow food to eat.

Today,

About 7,000 years ago, levers were used as balance scales in the ancient Middle East.

A balance scale is used to weigh things. If you put something you know weighs a pound on one side of the scale, you can put a bag of sugar on the other side of the scale, and when the lever is PERFECTLY STRAIGHT, you know you’ve got one pound of sugar!

Look at this picture. What class lever is a balance scale?

Ancient Egyptians used a tool called a shaduf to water their fields.

A shaduf uses a lever to dip a bucket into the Nile River. A worker swings the bucket over the fields so the plants can get a drink.

Levers have been helping us do work for thousands of years!

Once you start looking for them, you’ll find levers everywhere!