Energy:
Conservation and Transfer
Heat
• The transfer of energy between objects that are at 2 different
temperatures
Conduction
• Conduction is the transfer of heat by the
collision of particles; the particles must
touch in order to transfer heat. Metals
are considered good conductors since
they can speedily transfer heat. Stone is
also a moderately good conductor, but
wood, paper, air, and cloth are poor
heat conductors.
Convection
Transfer of heat from one place to
another by the movement of fluids or
gases
Radiation
• The energy radiated by electromagnetic waves through empty
space as a result of their temperature; heat travels outward from
its source
Transfer
• to convey or remove from one object, place, person, etc., to another
Electromagnetic Waves
• Electromagnetic waves are
formed when an electric field
(shown as blue arrows) couples
with a magnetic field (shown as
red arrows).
• When you listen to the radio,
watch TV, or cook dinner in a
microwave oven, you are using
electromagnetic waves.
Thermal Energy
Thermal energy is the energy of a
substance due to the movement of its
atoms or molecules. More the
molecules are moving about, the
higher the temperature.
Convection Cell
• Moving body of fluid due to the rise of heat and
fall (gravity) of cool gases until the heat is no
longer heated (Ex. Current/cycle)
• Convection cells are responsible for making
macaroni rise and sink in a pot of boiling water.
One of the forces that contributes to lava
erupting from a volcano is convection.
•
Insulator
• A material that does not conduct heat very well
• Ex: foam, paper, plastic, wood
Conductor
• A material that gets hot and cools off very quickly
• Ex: metal, water