Download Energy transformation notes

Law of Conservation of
Energy
• Energy cannot be created
or destroyed.
• Most forms of energy can be
transformed into other forms.
• Usually changes into thermal energy
due to friction.
Energy Conversion
• Energy can be changed
from one form to another.
– This is called an energy
conversion.
Kinetic-Potential Energy Conversions
• As a basketball
player throws the
ball into the air,
various energy
conversions take
place.
Kinetic-Potential Energy
Conversions
C
Most potential energy
Least kinetic energy
Mechanical energy at each
point is the SAME!!!!
B
D
As potential energy rises –
kinetic energy falls.
As kinetic energy rises –
potential energy falls.
A
E
Least potential energy
Most kinetic energy
Energy conversions
• All forms of energy can be converted into
other forms.
– The sun’s energy through solar cells can be
converted directly into electricity.
– Green plants convert the sun’s energy
(electromagnetic) into starches and sugars
(chemical energy).
– Our hands convert kinetic energy to thermal
energy when we rub them together.
Albert Einstein
Theory of Relativity
Energy can sometimes be
created by destroying
matter (nuclear reaction).
Single Transformations
• When 1 form of energy needs
to be transformed into
another to get work done.
• Ex: Toaster
Electrical Energy
Thermal Energy
Multiple Transformations
• When a series of
energy
transformations is
needed to do work.
• Ex: Listening to a
radio
Electrical Energy
Mechanical energy
(sound waves)
Kinetic energy
(eardrum vibrating)
Chemical and electrical
energy (nerve cells of
ear and brain)
Other examples of
energy transformations
• Rubbing your
hands together
Mechanical energy
Thermal energy
• Hydroelectric
plant
Mechanical energy
(of moving water)
Electrical energy
Other energy
conversions
– In an electric motor, electromagnetic
energy is converted to mechanical
energy.
– In a battery, chemical energy is
converted into electromagnetic energy.
– The mechanical energy of a waterfall is
converted to electrical energy in a
generator.
Energy Conversions
• In an automobile
engine, fuel is
burned to convert
chemical energy into
heat energy. The
heat energy is then
changed into
mechanical energy.