# temperature heat thermal energy

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```							Temperature, Heat and Thermal Energy
What is Temperature?
   Particles of matter are in constant motion. This
motion relates directly to the state of matter of
the object (solids, liquids, or gases).

   Temperature affects how fast these particles
move. The higher the temperature the faster the
particles move. Moving particles possess
kinetic energy.

   Temperature is defined at the average kinetic
energy of the particles of an object.
Temperatures You
Need to Know:
It is important to
know the freezing
and boiling points
of water.
Absolute zero                         oF   oC     oK
refers to the
temperature at         Water boils     212 100 373
which all
Room Temperature   72   23     296
movement of
particles in an       Water Freezes    32    0     273
object would stop!
Absolute Zero    -460 -273   0
Thermal Energy and Temperature:
   Thermal Energy is the sum total of all of the
energy of the particles of an object.
   Thermal energy and temperature are related
though DIFFERENT.
   Temperature is the average kinetic energy of the
particles of an object.
   Thermal energy is the total amount of energy of
the particles of an object.
   ?? A bathtub full of water at 100F has more thermal
energy than a thimble of water at 100F.
WHY????
Thermal Energy and Temperature:

More water at the same
temperature = more
thermal energy!!

Less water at same
temperature = less
thermal energy
Thermal Energy

   Which beaker of water has more
thermal energy?

80ºC              80ºC

A                 B
400 mL

200 mL
Thermal Energy - Answer
   Which beaker of water has more
thermal energy?
   B because it has more MASS!!!

80ºC                  80ºC

A                   B
400 mL

200 mL
Let’s Sum Temperature and Thermal
Energy Up!
   Temperature is a measure of the average heat
or thermal energy of the particles in a
substance. Since it is an average measurement,
it does not depend on the number of particles in
an object. It only depends on the amount of
Movement of those particles.
   THERMAL ENERGY is the amount of Movement
the particles have. Increasing the amount of
movement of the particles can increase the
amount of heat it has therefore it will increase
its temperature!!
Then, what is HEAT?
   Heat is really the amount of thermal energy
being passed from one object to another.

   Heat travels in a specific direction!!! ALWAYS
from the warmer object to the cooler object.

   So, if heat is the amount of thermal energy, then
the amount of heat an object has tells me how
much kinetic energy the object has.
   Ice = cold temp and very little movement = very little
heat/kinetic energy/thermal energy of its particles!!!
   Fire = high temp, a lot of movement, so high
heat/kinetic/thermal energy!!!
Heat Transfer

   Why does A feel hot and B feel cold?

80ºC                 10ºC

A                    B
Heat Transfer - Answer

   Why does A feel hot and B feel cold?
   Heat flows from A to your hand = hot.
   Heat flows from your hand to B = cold.

80ºC                     10ºC

A                       B
So…
When we take a temperature
we are seeing how much
heat has been transferred in
to an object. Based on the
amount of heat, the particles
will move a lot or a little.

Movement can keep the
temperature constant or
increase/decrease it.
Therefore, temperature is
directly related to heat and
heat is the amount of
thermal energy passed to an
object!!!
   Heat is always transferred
Heat Transfer       from hot to cold.

   Insulators slow the
transfer of heat/energy.

   Conductors allow the
transfer of heat, like
metals.

   Heat is transferred by
conduction, convection,
How is Thermal Energy Transferred?
3 MUST KNOWS!!!!!
Conduction – through direct contact!

Convection – through a gas or liquid , moves in currents!

Radiation – electromagnetic waves through
empty space, no medium required!
Conduction
   Heat is transferred
due to objects
touching each other or
through collisions.
   Occurs best through
solids.
   Heat continues to be
transferred until both
objects reach the
same temperature,
called a thermal
equilibrium.
Conduction
When you heat a metal strip at one end, the heat
travels to the other end.

As you heat the metal, the particles vibrate, these
vibrations make the adjacent particles vibrate, and so on
and so on, the vibrations are passed along the metal and
so is the heat. We call this? Conduction
Metals are different

The outer e______ of metal atoms
lectrons
drift, and are free to move.

When the metal is
heated, this ‘sea of
inetic
electrons’ gain k_____
energy and transfer it
throughout the metal.

ood       lastic
Insulators, such as w___ and p____, do not
have this ‘sea of electrons’ which is why they
do not conduct heat as well as metals.
Why does metal feel colder than wood, if they are
both at the same temperature?

Metal is a conductor, wood is an insulator. Metal
conducts the heat away from your hands. Wood
does not conduct the heat away from your hands as
well as the metal, so the wood feels warmer than
the metal.
Convection
   Transfer of heat
through a liquid or gas
through moving
currents, called
convection currents.
   The cause of wind and
weather.
Convection

What happens to the particles in a liquid or a
gas when you heat them?

The particles spread out and
become less dense.

What is a fluid? A liquid or gas.

This effects fluid movement.
Fluid movement

ense
Cooler, more d____, fluids
sink through w_____, less
armer
dense fluids.

In effect, warmer liquids and
gases r___ up.
ise

ink
Cooler liquids and gases s___.
Water movement

Cools at the   Convection
surface       current

Cooler                                  Hot water
water sinks                                 rises
Why is it windy at the seaside?
   Transfer of heat
through
electromagnetic
from the sun, a fire or
a light bulb.
   Transferred in all
directions.
   No contact required!
   Dark or dull objects
absorb more than light
or shiny objects do.
Emission experiment

Four containers were filled with warm water. Which
container would have the warmest water after ten minutes?

Dull metal                  Shiny black

Shiny metal                Dull black

shiny metal
The __________ container would be the warmest after ten
minutes because its shiny surface reflects heat radiation back
_______
dull black
into the container so less is lost. The ________ container
emitting
would be the coolest because it is the best at _______ heat
Absorption experiment

Four containers were placed equidistant from a heat lamp. Which
container would have the warmest water after ten minutes?

Dull metal                  Shiny black

Shiny metal                 Dull black

dull black
The __________ container would be the warmest after ten
minutes because its surface absorbs heat _______ the best.
shiny metal
The _________ container would be the coolest because it is
the poorest at __________ heat radiation.
absorbing
Heat Transfer
Summed UP!

   Heat:
   Thermal energy that
flows from a warmer
material to a cooler
material and,
   Like work, heat is...
   a transfer of energy!
   Can be measured in
Joules (J).

```
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