Levers

Objectives
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).
Time:
1-2 class periods
Materials:
Desk, ruler or meter stick,weight(apple, filled film can)
Prediction-Hypothesis-Question:
Does it make a difference on the ruler where you place a load when trying to lift it?
Procedure:
Have students explore with 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.
Record Results:
Have students record results as to how much effort was needed.
Extensions:
Have them now measure how far they have to push down to lift the weight 3 inches.
Have them move the load closer to the fulcrum.
Intro. that 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)

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