Transcript Ch 4 Sect 2

Ch 4 Sect 2
Energy Transfers and
Transformations
Movement of Energy
 Energy naturally moves from areas of
high energy to areas of low energy
 Ex-heat radiating off of a stove
 Transferring energy
 Energy stays in same form but moves to
another object
 Transforming energy Energy changes forms as it moves
Energy Transfers
 Electrical outlet can transfer electricity
 Example-Vandegraff machine
 Outlet
Machine
Human
 Heat energy can be transferred
 Example-boiling water
 Stove
Pot
Water
Energy Transformations
 Energy is like money in that it can be
used in different forms
 Electrical energy can be transformed to
 Light energy, Heat energy,
 Other examples?
Energy Transformations
 Chemical energy is transformed by living
organisms and machines
 Humans covert chemical energy into kinetic
energy
 Chemical energy in the body is stored as ATP or
Adenosine Tri-Phospate
Energy Transformations
 Machines also transfer chemical energy
into kinetic energy
 Chemical energy used by machines is
usually gas or diesel
 Suck, Squeeze, Bang, Blow
 4 steps that an internal combustion engine
uses
 Any engine in any gas powered vehicle
NRG Conversion in an Engine
 Sucks the air/gas in (intake)
 Squeezes the air (compression)
 Bang (gas ignites, causes explosion)
 Gasoline engines have a spark plug
 Diesel is explosive enough that it needs no
spark
 Blows air out (exhaust)
 How Car Engines Work
Mass, Atoms and Energy
 Mass in motion has energy
 Mass is made up of smaller parts called
atoms
 Atoms can be joined or broken apart to
produce energy
Nuclear Fusion
 Joining of 2 atoms to make 1 atom
 Bonds of both atoms are broken and
reformed to make one atom
 When bonds are broken energy is released
 Mass of the atom increases
 Nuclear Fusion Basics
Nuclear Fission
 Taking one atom and breaking it down to
two or more atoms
 Energy is released when the chemical bonds
are broken
 Mass of the atoms decrease
 Nuclear Fission Basics
Mechanical Energy
 Mechanical energy is the sum of total
potential energy and total kinetic energy
 Mechanical Energy = Pot Energy + KE
 Energy converts back and forth from PE to
KE but mechanical energy always stays the
same
 Ex. PE=70% and KE=30% ME=100%
PE=40% and KE=60% ME=100%
Law of Conservation of
Energy
 Conservation of energy states that
energy can neither be created or
destroyed, therefore amount of energy
always stays the same