Objectives: Students will be able to:
Time and Materials
Begin the discussion by
asking: What is a machine? (something that helps people do work).
Write a list of machines on the chalkboard: screw, hammer, washing
machine, scissors, power saw. Put screw on one list and washing machine
on another. What is the difference between these machines?
Elicit, one is powered by a person and the other by a motor. Discuss
each machine listed, placing it in its appropriate group, "Motor Machines"
and "Simple Machines". Today we'll discuss the simple machine known
as a lever.
A lever is a simple machine
that is used to push, pull or lift things. Draw a diagram of the
lever, fulcrum and load. Discuss the parts pictured. The lever
allows a person to lift a load that would normally be too heavy for
them to move.
Have a student demonstrate
how difficult it is to lift the cement block by themselves. Then
set up the plank on the fulcrum and set the concrete block on one end.
Then have a student push down on the end of the lever opposite
the load.
End the activity by
discussing the scientific procedures followed and give the students the
opportunity to respond in their Science Journals.
