2. Evidence of energy is everywhere! All you
need to do is look for motion, heat, and light.!
!
Energy is described by these characteristics:!
!
•Energy is the ability to do work.!
•Work is the application of a force through a
distance.!
•A force is a push or a pull that can put matter
in motion.!
•Motion is a change in distance or direction
with time.
3. Two types of Energy
Potential Energy !
• Water behind a dam!
• Car parked on a hill!
• Wound clock spring!
• Gasoline or sugar
Kinetic Energy!
!
•Falling Water!
!
•Car rolls down a hill!
!
•Clock’s hands move!
!
•Energy appears as
movement of the car or
body heat
8. FYI: How is electricity
made?
Usually a fossil fuel is burned to heat water.
The water turns to steam and forces a
machine called a turbine to turn. The turbine
powers a generator which generates
electricity.!
!
Summary: coal--hot water--steam--turbine--
generator--electricity!
!
A turbine can also be turned by falling water
and wind (wind mills).
9. Why should we not waste
energy?
When energy does work it changes from a
higher form of energy to a lower form. !
!
Example 1: Of the energy needed to light a!
light bulb, only 5% creates light......95% is!
lost as heat.!
Example 2: The chemical energy of!
gasoline is converted to heat in an!
automobile. Only 10% is converted into!
mechanical energy to move the car. The!
rest, 90%, is lost to the environment.
10. How can we save energy?
Conservation!
Recycle!
Reduce !
Reuse
Energy saved is energy
available another day.
Saving energy cuts down
on pollution and helps
our nonrenewable
resources last longer.
