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ENERGY
 Energy is unlimited and you need to
understand nature to harness them…
 What will happen when energy is used
up?
 How will life sustain if there is absence
of energy?
 What is energy?
What we know….
 Kinetic Energy
 Potential Energy
 Total energy (Mechanical energy)
 --------------------------------------------
 Chemical
 Solar
 Electrical
 Heat or Thermal energy
 Light
 Sound
 Etc….
Thermal Energy & Heat
Heat and Its Uses
Thermal Energy & Heat
16.1 Thermal Energy and Matter
THERMAL ENERGY & MATTER: Journal
1.
2.
3.
4.
5.
6.
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
 Heat flows DOWN the bar through
COLLISIONS.
 Collisions transfer thermal energy from hot to
cold.
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
 Thermal expansion/contraction - change in
volume of a material due to temperature
change.
Occurs because particles of matter collide more or less as
temperature changes.
Thermal expansion 
Also, wrap on beaker and lava lamp
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
Thermal Energy & Heat
16.2 Heat and Thermodynamics
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.
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!
THERMODYNAMICS
 The study of conversions between thermal energy
and other forms of energy.
THERMODYNAMICS
 First Law: Energy is Conserved
Thermal Energy & Heat
16.3 Using Heat
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.
PART 2 - USING HEAT
HEAT ENGINES
The two main types of heat engines are External combustion and
Internal Combustion
External = power plants
Internal = car engine
PART 2 - USING HEAT
External combustion – produces electricity at
power plants.
Water is heated by a fuel and the pressurized steam spins a
turbine.
http://www.eas.asu.edu/~holbert/eee463/coal.html
PART 2 - USING HEAT
HEAT ENGINES
External combustion – nuclear power plants.
USING HEAT
Internal combustion – car
engines.
The fuel (gas) is compressed
and ignited (lit) to drive a
piston.
USING HEAT
Internal combustion –
car engines.
Four-stroke engine.