Page 128 - Microsoft Word - LessonPlan-Overview.doc

Unit 4: Energy (Part 1) Page 7

Objectives

Lesson 2: Pulleys

When we played with levers we · Pulleys, like all simple
could see that, by using a simple machines, sacrifice distance
machine, we were able to use less for force. The more distance
the effort moves, the less
force to move a heavy object than
force is needed to lift the
we would have had to use if we
load.
didn’t use a simple machine. We
· Simple machines give you
also saw that with that lessening of
mechanical advantage.
force came an increase in distance.
· Mechanical advantage is
Obviously, you can only make a simply how many times
lever so long. After a while it gets easier it is to lift an object
kind of ridiculous. Imagine lifting a using a simple machine.

concrete block or a car with a Officially, mechanical
advantage is the factor by
lever. That’s a big lever and you
which a mechanism
probably still wouldn’t be able to
multiplies the force put into
lift the car very high. This is where it. A simple machine with a
pulleys come in. Are you ready? mechanical advantage of 100
Let’s get going. could lift a 100 pound load
with the effort of one pound.

Highlights for Solids:
· The pulley is a very powerful
simple machine.

· A major job of simple
machines is to decrease the
force needed to move
something.

· Flag poles, fishing rods,
cranes, window blinds, and

wishing wells all have
pulleys.

· The more pulleys that are
rigged together, the more

effective a pulley system can
be.

© 2010 Supercharged Science www.ScienceLearningSpace.com

128