Exploring Levers

First kind lever

Make a lever by laying a board across a pencil. When you push down one one end of the board, you can lift something on the other end. As you do this, the part of the board touching the pencil is not moving. In this context the pencil is called the fulcrum.

Use your lever to lift a rock (or the 2 N weight). What is the effect of putting the fulcrum in different places -- in the middle of the board, or closer to one end or the other?

Second kind lever

Here's another way to use a board to lift something. This is also a lever. Now the fulcrum is at the end of the board. Make this kind of lever, and try lifting the rock with it.

We have already met this kind of lever, and discussed the energy aspects of it. The energy you give to the system is the force you exert multiplied by the distance that your end of the lever goes; all this energy is given to the weight, and since it travels a different distance (smaller) the force is also different (larger).

A similar explanation can be given for the first kind of lever.

Here are some examples of levers you will find around the house. For each one, identify the fulcrum, and explain how the lever is used to make a job easier.

Can punch			Opening a paint can with a screwdriver
Pruner			Hammer claw

Check the box when you are done:   

pulleys