Heat is a form of:
Everything in the
universe has
heat energy!
Your BODY, your
CAR…even ICE!
Temperature:
 Temperature is ONLY a
measurement of particle
motion.
 Temperature measures the
average kinetic energy of the
molecules of an object or
substance.
SUMMARY:
HEAT IS
ENERGY
TEMPERATURE
IS A
MEASUREMENT
OF MOTION
3 Main
Temperature
Scales
1) Celsius
2) Fahrenheit
3) Kelvin
What you need to know about the Fahrenheit
Temperature Scale
1) Fresh water freezes at 32 degrees
Fahrenheit
2) Fresh water boils at 212 degrees
Fahrenheit
What you need to know about the Celsius
Temperature Scale
1) Fresh water freezes at 0 degrees Celsius
2) Fresh water boils at 100 degrees Celsius
3) It is the most commonly used scale
except for in the United States.
What you need to know about the Kelvin
Temperature Scale
1) There are NO NEGATIVE NUMBERS
2) Based on absolute zero (all molecule
movement has stopped).
3) The size of a Kelvin degree is equal in
magnitude (size) to a Celsius degree.
Temperature is measured with
thermometers.
There are several types of
thermometers.
THERMOMETER TYPES:
1) Liquid Thermometer
2) Bimetallic strip
3) Digital
Liquid Thermometer
Can only measure
temperatures in a certain
range.
Uses the expansion of
liquid alcohol or mercury
(Hg) to indicate changes in
temperature.
Bimetallic Strip
A coil is made using two
different metal strips
pressed together
Both strips expand and
contract at different rates
as the temperature changes
As the temperature
changes, the coil winds and
unwinds
DIGITAL THERMOMETERS
Measures temperature by
noting the change in
current
Changes in temperature
also cause electric
current to change in a
circuit
Heat moves from
objects with
higher energy
to objects
with lower
energy
HEAT CAN MOVE
IN 3 WAYS
1) CONDUCTION
2) CONVECTION
3) RADIATION
For heat to be transferred by
conduction:
 objects must be in direct
contact with each other—
 THEY MUST BE
TOUCHING!!!
Convection:
 Transfer of
energy by the
movement of
fluids with
different
temperatures
 For it to be
fluid, it can be
a liquid or a
gas!
Radiation:
 Transfer of energy
by electromagnetic
waves
 NO DIRECT
CONTACT!!!
 Does not require a
medium to travel!
 It is the only way
solar heat energy
can travel to Earth!
Some objects act as
conductors and
some act as
insulators.
A conductor is a
material that
transfers heat
quickly
An insulator is a
material that
slows the
transfer of heat
Specific Heat
 Describes how much
energy is required to
raise an object’s
temperature.
 The specific heat
value is how much
energy is required to
raise 1 kg. of a
substance by 1
degree Kelvin or
Celsius
 Denoted by “c” in
calculations.
Specific Heat Equation
Energy = (specific heat) x (mass) x
(temperature change)
OR
energy = cm t
The Kinetic Theory of
Matter explains the
behavior of
molecules in matter.
It states that all matter
is made of
constantly moving
particles that collide
without losing
energy.
When the temperature of a substance is
increased, its molecules move faster
and usually move farther apart. This is
thermal expansion. It occurs in all
forms of matter (there are a few
exceptions).
Water is an exception – it expands when it
is cooling from 4 degrees C to 0
degrees C.
There are four states
of matter:
1. Solid State
2. Liquid State
3. Gas State
4. Plasma State
For Solids:
• Particles are packed
closely together and
are constantly
vibrating in place
• Solids have a fixed
volume
• Solids have a fixed
shape
For Liquids
• The attractive
forces between
particles are weaker
than in a solid
• Particles can slide
past each other
• Liquids have a fixed
volume.
• Liquids do not have
a fixed shape.
For Gases
• Particles are farther
apart than in a
liquid or solid.
• Attractive forces are
weak.
• Gases have no
definite shape.
• Gases have no
definite volume.
For Plasma
• Most common state
of matter in the
universe
• Consists of
positively and
negatively charged
particles.
• No definite shape
• No definite volume
Changes in the
thermal energy of a
material can cause
it to change from
one state to
another.
Melting – When thermal
energy is added to a
solid, the change of a
substance from a solid
to a liquid is called
melting.
Heat of fusion – The
amount of energy
required to change 1
kg of a substance
from a solid to a liquid
at its melting point, or
when a liquid
becomes a solid.
Freezing – Phase change of
an object from the liquid
phase to the solid phase.
Vaporization – Change of a
liquid into a gas.
1. Evaporation-Vaporization
that occurs at the surface
of a liquid.
2. Boiling – Vaporization
occurring throughout the
liquid.
Condensation –
When a gas
changes into a
liquid.
To raise indoor air temperature
on a cold day, energy must
be transferred into a room’s
air by a heating system.
Heating system – Any device
or process that transfers
energy to a substance to
raise the temperature of the
substance.
Types of Heating
Systems:
 Forced Air
Systems
 Radiator Systems
 Electric Heating
Systems
Heating and Work increase thermal energy
 You can warm your hands by either
placing them near a heat source or
rubbing them together
 In this example, your hands would be
considered to be a system.
 A system can be a group of objects
you can draw a boundary around to
consider certain values about a
scenario.
THERE ARE 2 TYPES OF SYSTEMS:
 OPEN-Thermal energy can flow across
your “boundary” or if work is done across
the boundary
 CLOSED – Thermal energy is contained
within the “boundary” and no outside
work is done.
First Law of
Thermodynamics
The increase in the
thermal energy of a
system equals the work
done on the system
plus the thermal energy
transferred to the
system
Second Law of
Thermodynamics
Energy moves from
warmer objects (higher
energy) to cooler
objects (lower energy)
Cooling System – A device that transfers
energy as heat out of an object to lower
its temperature.
Cooling Systems use evaporation to transfer
energy from their surroundings using a
refrigerant
Refrigerant – A substance used in cooling
systems that transfers large amounts of
energy as it changes state