Transcript PS3EnergeticFormsChanges

Energetic Forms and Changes
Kinetic Energy =
Motion energy =
“Work in Progress”
Potential Energy =
stored energy =
Stored Work
Capability
Kinetic Energy
KE = ½ mv2
Kinetic Energy = ½ mass x (velocity)2
(Joules)
(kg)
(m/s)2
Gravitational Potential
Energy
PEg = m g h
Potential Energy = mass x gravitational x height
acceleration
(Joules)
(kg)
(m/s2)
(m)
Potential Energy
What is the potential energy at the
base of each step of the stairway?
Energy here PEg = mgh
PEg (initial) = KE (final)
mgh = ½ mv2
Energy here KE=½ mv2
Potential Energy
“Types”
Gravitational
Elastic
Chemical
Electrical
Nuclear
Gravitational Potential
Energy
Energy stored due to an object’s position above
the Earth’s surface; depends upon mass, height
from earth’s surface
Elastic Potential Energy
Energy stored by extension or compression
Chemical Potential Energy
Energy stored in the form of a substance’s
chemical bonds
Electrical Potential Energy
Energy stored as the result of electrical
charges (i.e., electrons)
Nuclear Potential Energy
Energy stored in the nuclei of atoms
Light Energy
An energy form defined as electromagnetic,
having wave-like characteristics
Sound Energy
An energy form considered to be transferred
as a mechanical (compression) wave
Thermal Energy
Represents the sum of the kinetic and potential
Energy of all the particles in an object/system
Q
=
m
∆T C
Thermal energy = mass x temp◦change x specific
change
heat
Joules
kg
◦C
J/kg◦C
Temperature is the term that describes the total
kinetic energy that results from the random motion
of a system’s atoms and molecules
Heating Curve / Phase Changes
Note thermal energy use in changing kinetic energy
of atoms/molecules, and in changing the nature of
the attractions between these same particles
(potential energy)
What might you hypothesize from the heating
curve for the mixture shown above?
Lab / Industrial Uses of Fractional
Distillation
ENERGY TRANSFER
BY
1) Radiation
2) Conduction
3) Convection
1) Radiation – Energy transfer
through space by visible light,
ultraviolet light, and other
forms of electromagnetic radiation
2) Conduction – Energy transfer that
occurs when mollecules collide;
conduction takes place only when
substances are in contact
3) Convection – energy transfer by the
flow of a heated / warmer substance
(meterology – the upward movement
of an air mass warmed by land or sea)