Transcript Conservation of Energy - Warren County Schools

Conservation of Energy
IT’S THE
LAW
Lifting a Ball
• When you lift a ball to a
certain height you
__________________.
• This work (W) is equal
to the weight of the ball
(w=mg) _______ the
height (h).
• The work done to lift
the ball is stored as
___________________.
PE = W = ____
h
W = Fd =wh = _____
Lifting a Ball
As the ball falls:
• Its Potential Energy
_________ because its
height ____________.
• Its Kinetic Energy
________ because it
____________.
• It turns out the amount of
potential energy lost as the
ball falls is the _________
as the amount of kinetic
energy the ball gains!!!!
PE = mgh
h
Kinetic Energy
Energy of Motion
The Law of Conservation of Energy
Energy cannot be created nor destroyed, it
can just be transformed from one form to
another, or transferred from one object to
another.
If we ignore any losses in energy to sound or
heat (two big sources) this means that ___ +
___ will always remain ______________.
A Falling Ball
A 2-kg ball falls from a height of 5-m. Trace its PE & KE as
it falls.
Height
5-m
PE=mgh
KE
PE+KE
4-m
3-m
5-m
2-m
1-m
0-m
Pendulums & Roller Coasters
• Pendulums and Roller Coasters must follow
the _______________________________
• IT’S THE LAW
• This means that what ever potential energy is
stored in each at the beginning is __________
back and forth between ____ & ____.
• If we are allowing for losses in energy from
heat and sound, then this amount of energy
slowly ___________.
A Pendulum
Roller Coasters
• Roller Coasters use the potential energy
stored when it is at the __________ and
converts it to _________ throughout the
ride.
• WEeeeeeeeee!!!!!!!!!