Download ME, PE, and KE part 2 - Kleins

Kinetic Energy
•
We already know that
Kinetic energy is energy
of motion
•
What does that mean?
•
What would energy of
motion require?
Kinetic Energy
•
Kinetic energy requires
motion
•
In order to be in motion
we must have a velocity
and object that is moving
•
Therefore, the Kinetic
energy formula uses both
mass and velocity
Kinetic Energy
•
The kinetic energy of a
moving object is always
equal to the work
required to bring it to that
speed from rest.
•
Net Force x Distance =
Kinetic Energy
Work-Energy Theorem
•
We know that there is a
relationship between
work and energy
•
We can say that work will
change kinetic energy
•
If no change in energy
occurs then no work is
done
•
This is also true for
potential energy
Conservation of Energy
•
Now that we know what
energy is, we need to
understand how it
behaves, how it
transforms.
•
In order to look at this we
need to analyze energy
as a transformation from
one form to another
Conservation of energy
•
If you launch a marble
from a sling shot and hit
a fence, we know that the
potential energy of the
rubber band will equal
the kinetic energy of the
marble.
•
If the marble hits a fence
it delivers its kinetic
energy to the fence post.
•
The work done on the
post should equal the
force of impact x the
Conservation of Energy
•
The work done on the
fence however does not
equal the energy from
the marble.
•
This is because some of
the energy is transformed
into heat from the impact.
•
The amount of energy
used to heat the fence
equals the amount of
energy difference
between the marble and
Entropy Slayer 2000
•
Entropy Slayer 2000
Law of conservation of
Energy
•
Energy can not be
created or destroyed. It
can be transformed from
one form into another,
but the total amount of
energy never changes.