BACKGROUND:
An inclined plane allows energy to be
transferred over a longer distance, so you usually need less energy to
accomplish the task. A ramp is an inclined plane and a wedge is a double
incline plane. A ramp helps move items to a higher level without as much
work. A wedge helps get in between something.
A lever helps lift things easily. It
is used with a fulcrum that can be moved to help the lever be more
efficient. Your arm is a lever, with the elbow and shoulder as a
fulcrum. A see saw is also a lever. If you move the fulcrum, you can
pick up heavy objects.
A wheel and axle help to move heavy
objects. A pulley has two or more wheel and axles. If the size and
position are arranged correctly, you can move heavy objects easily.
PROCEDURE:
- Describe a ramp, wedge, lever, and
pulley. Use the worksheet to illustrate pulleys, wedges, levers, and
ramps. An overhead of the worksheet helps go over the components of each
of the simple machines. A ramp is a inclined plane. A wedge is two
incline planes. A lever has two components, a fulcrum and a plane. The
fulcrum can help direct energy to make the lever work more efficiently.
A pulley is two wheel and axles to make movement assist in producing
more work efficiently.
- Depending on your equipment,
demonstrate the following with your students assistance.
PULLEY: Try lifting a bucket of rocks or
blocks without using a pulley. Then using a pulley, demonstrate how
easy it is to lift the bucket.
RAMP: Pose the following questions: To
drive a truck up a mountain, how must the road be made? Can a truck go
up stairs? No, it needs a ramp.
LEVERS: Using a
board and a fulcrum (half log) see if the students can figure out how
to lift you. Don't give them too many clues, hopefully they will know
to move the fulcrum closer to you.
WEDGE: Ask the students how to cut wood.
If you have an axe, show them how it is shaped in the form of a wedge.
However, warn students that the axe can be dangerous because the
energy from the person who is using the axe is concentrated on the tip
of the wedge.
