LEVER:

LEVER: The lever is a simple machine made with a bar free to move about a fixed point called a fulcrum.

There are three types of levers.

A first class lever is like a teeter-totter or see-saw. One end will lift an
object (child) up just as far as the other end is pushed down.

A second class lever is like a wheel barrow. The long handles of a wheel
barrow are really the long arms of a lever.

A third class lever is like a fishing pole. When the pole is given a tug, one
end stays still but the other end flips in the air catching the fish.

ACTIVITY

1. Draw each type of lever, by using the items above, label the fulcrum, effort, and object to be moved (or force).

2. Find other examples of levers and classify them as first, second, or third class.

ACTIVITY: What happens when the distance is changed between
the fulcrum and the effort force?

MATERIALS

5 large washers taped together
30 cm ruler
pen

1. Place washers on top of ruler at the 1 cm mark.
2. Place the pencil under the ruler at the 10 cm.
3. Push down on the 30 cm mark (effort force).
4. Move pencil to 15 cm mark and again push down at 30 cm mark (effort force).
5. Compare your effort force in steps 3 & 4.
6. Move pencil to 20 cm mark and again push down (effort force).
7.What class lever is this?

To WORK IS SIMPLE WITH SIMPLE MACHINES