About the Lever: This simple machine has been around for thousands of years. Levers are used to increase force to move objects. They are composed of two parts, the handle and the fulcrum. To move the object, push on the handle. The fulcrum is the point on which the lever balances. Seesaws and bottle openers are levers. A fork is a lever in which your hand is the fulcrum. To demonstrate a lever to your class, take the children to an open area outside.Vocabulary
lever, simple machine, force, motionFor this activity, you will need:Plank (approximately 40 inches long)Log (a section of wood similar to what you would burn in a fireplace)Large rock (with uneven edges)Chart paper and markersDirections
1. Demonstrate that the rock is too heavy to pick up by letting the children try to lift the rock.
2. Place the log a short distance from the rock.
3. Rest the plank on the log, pushing one end under the edge of the rock.
4. Push down on the other end of the plank till the rock begins to lift up.
5. Encourage the children to take turns using the lever to lift the rock.
6. In the classroom, record the children’s responses on a chart titled, “What We Learned About Levers.”