# Thermal Energy - mkbaker_1_

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```					          Thermal Energy

Chapter 6 Section 1
Temperature & Heat
Part 1
Warm Up:
• To shape metal into a horseshoe, the metal is
heated in a fire. Why will a horseshoe bend
when it’s very hot, but not after it cools?
What was different ?
• There was            • Matter is
more motion in         always in
the hot water          motion

• Particles of
gases,
liquids, and
solids all
• The energy of
move
motion is Kinetic
Energy
Heat
Heat is related to
temperature:

The Temperature of
an object is the
measurement of the
average kinetic energy
(KE) of particles
What do Temperature Scales
Measure?
• Fahrenheit: used in US
• Celsius: used in other countries
• Kelvin: SI unit
0 K = -273°C
0°C = 273 K
Thermal Energy
• Thermal Energy (Q) is the sum of the
kinetic energy + the potential energy of all
the particles in an object:
Q = KE + PE
Thermodynamics
• First Law of           –Energy is
Thermodynamics:         CONSERVED
the increase in
thermal energy of a
system equals the
work done on the
system plus the heat
transferred to the
system
Open Systems
• In an open system, heat flows across the
boundary, or work is done across the
boundary.
• What are examples of open systems?
Closed Systems

• In a closed system, no heat flows across
the boundary and no work is done across
the boundary.
• What are examples of closed systems?
Thermodynamics
• Second Law of
Thermodynamics:
Heat flows from
warmer objects to
cooler objects
Heat cannot flow from
a cooler object to a
warmer object unless
work is done
How do solids transfer heat?
• Conduction: the
transfer of thermal
energy by collisions
between particles in
matter.

• Particles in solids
vibrate and collide
with each other
• List 3 examples
of conduction
Convection
• Convection is the
transfer of thermal
energy in a gas or
liquid by the
movement of warmer
and cooler fluid from
place to place.
Knowing this, what will happen to a piece of ice floating at the top of a
warm glass of water?
What will happen to a piece of ice at the bottom of a glass of water?

• List 3 examples of convection
• Radiation is the transfer of
energy by electromagnetic
waves. These waves
travel in the empty spaces
between particles until their
energy is absorbed by a
particle.