Transcript Energy Transformation

Energy Transformation
The process of energy changing
from one form to another
Example
 This process is happening all the time
in the world around us and even in us.
 When we consume food our body
utilizes the chemical energy in the
bonds of the food and transforms it
into mechanical energy, a new form of
chemical energy or thermal energy.
physical sciences application.
• The ability for energy to be transformed
automates, lights, entertains, and warms
our world in an astounding multitude of
ways.
common activities illustrations
• 1.An engine, such as the engine in your
car, converts the chemical energy of
gasoline and oxygen into the mechanical
energy of engine movement.
•
Another illustration
• 2. A light bulb changes the electrical
potential energy into electromagnetic
radiation (light and heat).
•
Even another illustration
• 3. Windmills harness the energy of the
wind and convert it into mechanical energy
in the movement of the turbine blades,
which is then converted to electrical
energy.
•
Last of many more
 4. Solar panels transform light to
electricity OR to heat (solar-cooker)
Matter and Energy
• There are 4 fundamental states of matter:
solid, liquid, gas and plasma. We will
concern ourselves only with the first three
since the plasma state does not occur
commonly in on Earth. (Although it is the
most common state in the universe, in
stars)
Matter Solid
• In solids, molecules are tightly packed
together. The molecules of a solid do
move, however their movement is very
limited.
Matter Liquid
• As you add energy to ice in the form of
heat, you increase the amount of
movement by each molecule.
• This movement eventually causes the
solid ice to turn into liquid water
Energy Transfer
• Energy can be transferred from one
location to another, as in the sun's energy
travels through space to Earth. The two
ways that energy can be transferred are
by doing work and heat transfer.
Doing Work
• Adding energy to an object by pushing
• If a force is exerted and the object moves
as a result, then work is done
Doing Work
• Energy can be transferred from one object
to another by doing work. When work is
done on an object, it results in a change in
the object's motion (more specifically,
Energy is often defined as the ability to do
work. Work equals force multiplied by
distance. change in the object's kinetic
energy). Work = Force x distance
Heat Transfer
More about Heat Transfer
• Heat is transferred when thermal energy
moves from warmer to colder.
• Thermal energy can be transferred in
three ways: by conduction, by convection,
and by radiation.
The Transfer Process
• Conduction
• Conduction is the transfer of energy
from one molecule to another
• Sort of like direct contact in pool.
More about transfer
• This transfer occurs when molecules hit
against each other, similar to a game of
pool where one moving ball strikes
another, causing the second to move.
Conduction takes place in solids, liquids,
and gases, but works best in materials that
have simple molecules that are located
close to each other. For example, metal is
a better conductor than wood or plastic.
Convection
• Convection is the movement of heat by
a liquid such as water or a gas such as
air.
• The liquid or gas moves from one location to another, carrying heat
along with it. This movement of a mass of heated water or air is
called a current.
Radiation
• Heat travels from the sun by a process
called radiation. Radiation is the transfer
of heat by electromagnetic waves. When
infrared rays strike a material, the
molecules in that material move faster. In
addition to the sun, light bulbs, irons, and
toasters radiate heat
Thermal (Heat) Energy
• Heat is given off whenever energy is
being used. You can tell if a television has
been on by feeling if it is warm. When you
run up a flight of stairs you feel warm
because you are burning food energy.
D4 : Energy Transformation among
voltage, current, and resistance
• Simple series circuit.
• Simple Series Circuit
Diagram
Series Circuits
• When you flip a light switch on and off, you
are closing and opening a circuit.
• A circuit is the path that electricity follows.
• For electrons to travel (creating an electric
current), the circuit must be closed.
• When you flip the light switch off, you are
opening the circuit and the lights turn off.
• When you flip the switch on, the circuit it
closed and the lights come on.
Series Circuit VOLTAGE
• Electromotive force, or EMF (sometimes called
electrical pressure) causes the electrons to
move in an electrical circuit.It is the force that
makes electrons move in a certain direction
within a conductor.
• But how do we create this “electrical pressure”
to generate electron flow? There are many
sources of EMF. Some of the more common
ones are: batteries and generators, just to name
a few.
The Volt
• Technically (very technically), one volt is
defined as the electrostatic difference
between two points when one joule of
energy is used to move one coulomb of
charge from one point to the other.
Current
• electrical current will
flow as the electron
moves from the
negatively charged
area to the positively
charged area
•
•
EMF is electromotive
force. EMF causes the
electrons to move in a
particular direction.
EMF is measured in
units called volts.
Resistance
• Define resistance and
how we measure it.
• Discuss the
similarities between
resistance in a wire
and the resistance in
a water hose.
Ohms:Resistance is a term
that describes the forces
that oppose the flow of
electron current in a
conductor
• Resistance is also good
because it gives us a way
to shield ourselves from
the harmful energy of
electricity
OHM’s Law
• Calculate the amount
of electric current in a
circuit using Ohm's
law.
• OHM'S LAW
• I = V/R,
• I = current, V = voltage,
and R = resistance
• V=IxR
• R = V/I
D5: Electricity Energy
Transformation
• Electricity is a term used to describe the
energy produced (usually to perform work)
when electrons are caused to directional
(not randomly) flow from atom to atom. In
fact, the day-to-day products that we all
benefit from, rely on the movement of
electrons. This movement of electrons
between atoms is called electrical
current.
Electricity Energy Transformation
to heat, light, and motion
• Transformation to
Heat
• Transformation to Light
• Transformation to Motion