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)
Go
to Catapult Shooter
Go
to Tiny Levers
Go
back to the Machine Index