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Potential VS. Kinetic Energy
Energy – The ability to do work
How is energy involved in
the following picture?
The tennis player does work
On her racket
The racket does work on the
ball
The ball does work on the
net
Energy Video
http://player.discoveryeducation.com/index.cfm?guidAssetId=2FBE6C5D-0DD3-4210-B4761A679001C8EE&blnFromSearch=1&productcode=US
What is energy?
• “the ability to do work”
• The combination of energy and matter
make up the universe:
– Matter is substance, and energy is the
mover of substance.
Energy
Examples
• Examples are: light energy, heat energy,
mechanical energy, gravitational energy,
electrical energy, sound energy,
chemical energy, nuclear (atomic) energy.
• These forms of energy can be transferred
and transformed between one another. This is
of immense benefit to us.
The Law of Conservation of
Energy
• Energy cannot be created or destroyed; it
may be transformed from one form into
another, but the total amount of energy
never changes.
Energy is
nature’s way of keeping score.
• We sense energy
only when the score
changes.
• Either a
transformation from
one form of energy to
another,
• or a transfer of
energy from one
point to another.
STATES OF ENERGY
Potential - Stored Energy or energy that
is waiting to be transferred.
-Object is not moving or doing work.
-When work is done on an object, potential
energy is stored.
-Has the ability to turn into kinetic energy.
What is Potential Energy?
o Energy that is stored
and waiting to be
used later
Examples: stretched
rubberband, roller coaster
at the top of a hill, a diver at
the end of the diving board
waiting to jump.
STATES OF ENERGY
Kinetic - The energy of motion, when
energy is being transferred.
The faster the motion, the more kinetic
energy it has. The bigger the mass, the more
Kinetic energy it has.
What is Kinetic Energy?
o Energy an object has due
to its motion
o Examples: roller coaster
going down a hill, baseball
flying through the air,
wind blowing, etc.
Potential
• energy of position
or energy in
storage.
– Water behind a dam
– Hammer over head
– Food on the plate
Kinetic
• energy of motion,
the form capable of
doing work
– Flowing water
– A falling hammer
– Electrons regenerating
ATP in a bio’l cell
The Roller Coaster
http://www.ohiomathworks.org/themeparks/coastequation.gif
How is all energy divided?
All Energy
Potential
Energy
Gravitation
Potential
Energy
Elastic
Potential
Energy
Kinetic
Energy
Chemical
Potential
Energy
What is Gravitational Potential
Energy?
Don’t look down,
Rover!
Good boy!
o Potential energy
due to an object’s
position.
o P.E. = mass x
height x gravity
Gravitational Potential Energy
Depends on:
1) Mass
2) Height of object (more height =
more potential).
3) Gravity pulling on object (objects on
earth would have more potential
energy than objects on the moon
due to more gravitational pull on
earth).
What is Elastic Potential Energy?
o Potential energy due to compression
or expansion of an elastic object.
Notice the ball compressing
and expanding
Elastic Potential Energy
• Examples:
What is Chemical Potential Energy?
o Potential energy
stored within the
chemical bonds of
an object
Chemical Potential Energy
Factors that Affect Potential
Energy
• m = mass (kg)
• h = height (m)
• g = accel due to
gravity
– (9.8 m/s2)
Factors that Affect Potential
Energy
• Mass= the more
mass an object
has, the more
potential energy it
has.
Factors that Affect Potential
Energy
• Height = the higher the
object is placed, the more
potential energy it has.
Factors that Affect Potential
Energy
• Gravity = the more
gravity pulling on
an object, the more
potential energy it
has.
Factors that Affect Kinetic
Energy
• Mass = the more
mass an object has,
the more kinetic
energy it has.
Why would a high speed collision
cause more damage than a low
speed collision?
Factors that Affect Kinetic
Energy
• Speed or Velocity =
the more speed an
object has the
more kinetic
energy it has.
Diver A
Fastest
Diver B
What is the source of our
energy?
• The source of
practically all
our energy is
the Sun.
What is Mechanical Energy?
o Energy due to a
object’s motion
(kinetic) or position
(potential).
The bowling ball has
mechanical energy.
When the ball strikes
the pins, mechanical
energy is transferred
to the pins!
Examples of Mechanical Energy
What is Electromagnetic
Energy?
o Light energy
o Includes energy from
gamma rays, xrays,
ultraviolet rays,
visible light, infrared
rays, microwave and
radio bands
What is Electrical Energy?
o Energy caused by
the movement of
electrons
o Easily transported
through power lines
and converted into
other forms of
energy
What is Chemical Energy?
o Energy that is
available for release
from chemical
reactions.
The chemical bonds in
a matchstick store
energy that is
transformed into
thermal energy when
the match is struck.
Examples of Chemical Energy
What is Thermal Energy?
o
Heat energy
o The heat energy of an
object determines how
active its atoms are.
A hot object is one whose atoms
and molecules are excited
and show rapid movement.
A cooler object's molecules and
atoms will show less
movement.
QUIZ TIME!
What type of energy
cooks food in a
microwave oven?
ELECTROMAGNETIC
ENERGY
What type of energy is
the spinning plate
inside of a microwave
oven?
MECHANICAL ENERGY
QUIZ TIME!
Electrical energy is
transported to your house
through power lines.
When you plug an electric fan
to a power outlet, electrical
energy is transform into
what type of energy?
MECHANICAL ENERGY
QUIZ TIME!
What energy transformation
occurs when an electric lamp
is turned on?
ELECTRICAL ENERGY

ELECTROMAGNETIC ENERGY
What types of energy are shown below?
Mechanical and Thermal Energy
(Don’t forget friction)
What type of energy is shown below?
Chemical Energy
What types of energy are shown below?
Electrical, Mechanical and
Electromagnetic Energy
What type of energy is shown below?
Chemical Energy (yummy)
What type of energy is shown below?
Thermal Energy
What types of energy are shown below?
Mechanical, Electromagnetic,
Electrical, Chemical and Thermal
Energy
The Law of Conservation of
Energy
• Energy cannot be created or destroyed; it
may be transformed from one form into
another, but the total amount of energy
never changes.