Download What is Energy?

Forms of Energy
States of Energy
 What
is Energy? Energy
is the ability to cause a
change or do work

There are 2 states and 6
forms of energy
States of Energy
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page (again, divide it in half)
Potential Energy
Kinetic Energy
Potential Energy
• PE is stored energy due to its vertical position
or (molecular) arrangement
3 Types of Potential Energy
1. P.E. due to its position is known as gravitational
potential energy
– gpe depends on height and mass of object
– Calculate gpe using formula:
PE = m∙g∙h
(m=mass, g=gravity, h=height)
2. Chemical P.E. is energy stored in atoms of
elements and compounds
3. The elastic potential energy an object has
results from how much it is stretched or
compressed.
Examples:
• A cat in a tree. (gpe)
• Food (chemical PE)
• A stretched bow (elastic PE)
Kinetic Energy
• Is the energy of motion
• KE depends on speed and
mass of the object
• Calculate KE using formula:
KE = ½ mv2
Examples:
• A cat falling out of a tree
• Heat given off when wood
is burned (the molecules
are moving fast)
• Food digesting (the
molecules in the food and
the stomach acid are
changing into different
chemicals providing the
energy our muscles need to
move)
MR. C. NET
MECHANICAL
RADIANT
CHEMICAL
NUCLEAR
ELECTRICAL
THERMAL
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MECHANICAL ENERGY
• Mechanical Energy is the energy
produced by moving objects (it’s the
total energy of an object’s motion
(KE) and position (PE) of an object).
(KE + PE)
• Sound energy is a type of mechanical
energy; it’s produced by an object’s
vibrations.
– Examples: running, leaves
rustling, ball rolling, whistling
RADIANT (LIGHT) ENERGY
• Radiant Energy is light energy given off
in the form of waves and particles
(called photons) (see it)
• Most light energy is not visible to
human eyes; radiant energy is a part of
the electromagnetic spectrum. (see it)
• The Sun is the Earth’s main source of
radiant energy
• Infrared radiationproduces heat in form
of waves
How microwaves
work
CHEMICAL ENERGY
Bonds break between
compounds and release
energy
• Chemical Energy
is the energy
produced when
the bonds
between atoms
and molecules
are broken and
rearranged
(during chemical
reactions).
• Examples:
photosynthesis,
digestion,
battery (stored
energy), coal
(stored energy)
NUCLEAR ENERGY
FISSION (splitting of nuclei)
FUSION (joining of nuclei)
Nuclear Energy is the energy released from a
nuclear reaction in the nucleus of an atom; the
nucleus of an atom can break apart (fission)
or nuclei can join together with others
(fusion).
•Examples: atomic bomb (fission),
formation of a Star (fusion)
ELECTRICAL ENERGY
•Electrical Energy is the energy produced
by moving electrons. Electrons are
negatively charged particles found in
atoms.
For example: Toasters, TVs, Light bulbs
all use electrical energy
THERMAL (HEAT) ENERGY
Thermal Energy is the energy produced
by moving atoms and molecules; moving
atoms create heat
•Infrared waves, which are a part of the
electromagnetic spectrum, also produce
thermal energy.
For example: the sun, a fire, a stove top,
or two objects rubbing together give off
heat energy
see it
ENERGY
TRANSFORMATION/
CONVERSION NOTES
• When work is done on an object, energy is
transferred (passed on) to the object.
– For example: when kicking a ball, the energy
transfers from your foot to the ball.
ENERGY CONVERSIONS -when energy
changes from one form or state to another.
• Energy can change states (PE  KE); this is
an energy conversion
– Energy can change from PE to KE to PE again and
vice versa.
• For example: a roller coaster ride, a yo-yo or
a skier
– Energy can change forms, too; this is
called an energy conversion
• For example: a battery changes chemical
energy into electrical energy
• A flashlight changes electrical energy into
radiant energy
What is the Law of
Conservation of
Energy?
• It states that energy in a system can be
converted from one form to another or
from one object to another, but the total
amount of energy stays the same; the
energy in a system is neither created nor
destroyed.
• A system is set of connected
(interrelated) things or parts forming a
complex whole.
What is a “Law”,
scientifically speaking?
Observations
Hypothesis
Experiments
Theory
Law
• A law is a
statement which
explains some
kind of regularity
of nature.
Theories might
help to explain
the cause(s) of a
law’s regularity.
A scientific law represents a hypothesis (or group
of related hypotheses) which has been
confirmed through repeated testing, almost
always conducted over a span of many years.
Generally, a law uses a handful of
fundamental concepts and equations to define
the rules governing a set of phenomena.