Transcript Thermal Energy & Heat THERMAL ENERGY & MATTER

Thermal Energy & Heat
THERMAL ENERGY & MATTER: Journal
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In which direction does heat flow spontaneously?
Define TEMPERATURE
How is THERMAL ENERGY transferred?
What are the factors that determine the THERMAL
ENERGY of a material?
Which type of material heats more, one with a high specific
heat, or one with a low specific heat?
Is WORK 100% efficient? How do you know?
THERMAL ENERGY & MATTER
 Work and Heat- work is never 100% efficient. Some
is always lost to heat.
THERMAL ENERGY & MATTER
 Heat- the transfer of thermal energy from one object
to another because of a temperature difference.
In what direction does heat flow spontaneously?
FROM HOT to COLD
THERMAL ENERGY & MATTER
 Temperature = measure of how hot or cold something
is compared to a reference point.
Temperature is the average kinetic energy of the particles
in an object.
In the image below, where is average kinetic energy
greater?
Higher temperature 
THERMAL ENERGY & MATTER
 Thermal energy- total potential and kinetic energy in
an object. It depends on mass, temperature, and phase
of an object.
If both objects are in the same phase & at the same temperature,
which one has MORE thermal energy?
 Because there
are MORE
particles moving
around.
THERMAL ENERGY & MATTER
 Specific Heat – amount of heat needed to raise ONE
gram of a material ONE degree Celsius.
THERMAL ENERGY & MATTER
 The LOWER a material’s specific heat the MORE its
temperature rises when energy is added.
Which will heat faster (has the lower specific heat)?
Water?
Specific heat of water = 4.18 J/g°C
Or Lead?
YES!
Specific heat of lead = 0.46J/g°C
Heat Transfer:
 3 methods of heat transfer:
 conduction, convection, and radiation.
Crust forming on the surface of lava is an example of a
change of state by transferring heat from the hot lava to
the10 cooler air surrounding the lava.
HEAT TRANSFER
 What type of HEAT TRANSFER is occurring in the
pictures? Conduction, convection or radiation?
CONDUCTION –
The transfer of thermal energy with no transfer of
matter. Must be Touching!
HEAT TRANSFER
 What type of HEAT TRANSFER is occurring in the
pictures? Conduction, convection or radiation?
CONVECTION –
The transfer of thermal energy when particles of a liquid
or gas move from one place to another
HEAT TRANSFER
CONVECTION – in the earth and sun
HEAT TRANSFER
 What type of HEAT TRANSFER is occurring in the
pictures? Conduction, convection or radiation?
RADIATION –
The transfer of thermal energy by waves moving
through space. ALL OBJECTS radiate energy!
THERMAL ENERGY & MATTER: Journal
Define Convection, Conduction and
Radiation
2. Give an example of each.
3. Write a sentence describing how each is
important to our everyday lives.
4. How do we use heat in our everyday lives?
1.
Where does heat transfer on this beach?
Label at least four examples
of heat transfer on the
picture.
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Diagram Answers:
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Methods of Heat Transfer
 Think-Pair-
Share!!
 Discuss
examples of
each type of
heat transfer
with a partner
for two
minutes.
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Methods of Heat Transfer
Convection: Heat
transferred by the
motion of a
substance
Conduction:
Heat
transferred
by touching
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Radiation: Heat
transferred
through as waves
through space