What is a lever? A lever allows you to put a force on one place, an for it to be multiplied up to work somewhere else. This lets you do something that would be impossible if you used direct force. A crowbar is an example of a lever.

Lever

What is a lever? A lever allows you to put a force on one place, an for it to be multiplied up to work somewhere else. This lets you do something that would be impossible if you used direct force. A crowbar is an example of a lever. You could not directly pull a nail out of a piece of wood, but using a crowbar, you can.

A lens changing the path of the light rays.

Did you realise that you already have simple machines built into your body?
Your upper and lower arms are simple levers, for example. A lever is made of a load, a pivot and effort (or force). The load is the object that is moved or lifted, in this case dumbbells. There are two pivot points – your shoulder and your elbow, and the force is applied by your muscles.

If you had very short arms you wouldn’t be able to lift as much weight as if you had long arms.

By exerting a force on one end of the lever (your arm), a force at the other end of the lever (your hand) can lift weights.

Levers can be obvious, such as crow bars, or they may be hidden, as is shown by the video below.

Video: Decorative lever.

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