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LEVER: A lever is a rod that rests on a support called a fulcrum. It is used to lift or move loads. |
| Objectives: | Student will be able to: identify a lever as a rod that rests on a support called a fulcrum, make a lever and explore how it is used to make work easy. |
Materials:
- Science Journal
- desk
- ruler or meter stick
- weight (apple or filled film can)
| Question: | Does it make a difference where you place a load on a ruler when trying to lift it? |
Procedure:
- Have students explore with a ruler and a weight.
- Have them put ruler on a disk with different lengths of the ruler hanging over the edge of the desk.
- Or have the students put the 4 inch mark on the edge of the desk. Put the weight on 12 inches. Push down on the ruler.
- Now put the 8 in. mark at the edge of the desk. Push down. Have them move the load closer to the fulcrum.
Journal:
- Have students record results as to how much effort was needed.
- Introduce the formula W= force(f) x distance(d)
- Work (lifting the weight)= Force(how hard you had to push down on the ruler) x the Distance (how far down you had to push the ruler)
| Conclusion: | The closer a load is to the fulcrum, the less effort is needed. The less effort means more distance to move the effort. Work is the amount of force times the distance (how far down you had to push). |
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