Page 129 - Microsoft Word - LessonPlan-Overview.doc
P. 129
Unit 4: Energy (Part 1) Page 8
Textbook Reading
Everything in the entire apple up a flight of stairs, I would
universe can be categorized be doing work. I would be moving
into two things, matter and the apple against the force of
energy. As a matter of fact, gravity over a distance. However, if
according to Einstein and some I were to push against a wall with
relatively new physics theories all my might, and if the wall never
(string theory) even matter is moved, I would be doing no work
actually energy incarnate. Energy because the wall never moved.
can become matter and matter can (There was a force, but no
become energy. Makes your head distance.)
spin, right? So what is energy?
Another way to look at this, is to
What is Energy? say that work is done if energy
is changed. By pushing on the
Energy has a number of different non-moving wall, no energy is
forms; kinetic, potential, thermal, changed in the wall. If I lift the
chemical, electrical, apple up a flight of stairs however,
electrochemical, electromagnetic, the apple now has more potential
energy then it had when it started.
sound and nuclear. All of which
measure the ability of an object or The apple’s energy has changed,
system to do work on another so work has been done. (We’ll
object or system. In the physics define potential energy more in
books, energy is the ability to another lesson.)
do work.
How is Energy Measured?
What is Work?
If we wish to talk about energy
further, we need to have a unit of
Work is the exertion of force
over a distance. In our mechanics measurement. For energy, a
block we defined force as a push or couple of units are the Joule and
the calorie. A Joule is the energy
a pull. So, work is when something
gets pushed or pulled over a needed to lift one Newton one
meter. A Newton is a unit of force.
distance against a force.
Mathematically it’s Work = Force x One Newton is about the amount of
Distance or W = fd. force it takes
to lift 100
Let me give grams or 4
you a few ounces or an
examples: If I apple.
was to lift an
© 2010 Supercharged Science www.ScienceLearningSpace.com
129
