Transcript Energy - GEOCITIES.ws

Energy
Mrs. Wolfe
Two Forms of Energy
ENERGY
• Kinetic Energy –
Energy of MOTION
• Potential Energy –
STORED Energy
Time for a game!
• SIMON SAYS!
– Kinetic energy: JUMP
– Potential energy: STAND STILL
Kinetic Energy
• Energy of Motion
• KE = ½ mv2
• Which has the most KE?
80 km/h truck
• Which has the least KE?
50 km/h motorcycle
80 km/h
50 km/h
80 km/h
Practice Problem:
• Homer Simpson sends a bowling ball toward Bart’s
head at a velocity of 200 m/s. The bowling ball has
a mass of 20 kg. How much kinetic energy does this
ball have?
• KE = ½ mv2
• KE = ½ x 20 x (200)2
• KE = 400,000 J
• *ALWAYS do the square first!!
UNITS!??!
• Energy is measured in JOULES (J).
Potential Energy
• Stored Energy
• PE = mgh
• G = 9.8 m/s/s
• Which boulder
has MORE PE?
Potential Energy
• What other ways can
an object store
energy?
Look at Potential Energy!
Time for VIDEOS!!
Practice Problem:
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What is the potential energy of EACH plane?
PE = mgh
PE = (800)(9.8)(10,000)
PE = 78,400,000 J
PE = (800)(9.8)(9,000)
PE = 70,560,000 J
Time for a WS then a Lab!
• Kinetic & Potential Energy Math WS
• Kinetic & Potential Energy Lab
Specific Forms of Energy
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Mechanical –
Thermal –
Sound –
Electromagnetic
Chemical –
Mechanical Energy
• Energy of moving
objects
– Car traveling down the
road
– Ball flying through the
air
– Windup toy walking
– You picking up a glass
Thermal Energy
• Heat Energy; occurs
when atoms vibrate
faster (friction)
– Heating water
– Fire
Sound Energy
• Vibration of atoms in
the air that hit our
eardrum and register
in our brains as sound.
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Crackling
Popping
Banging
Etc.
Electromagnetic Energy
• Energy from forces
between positive and
negative charges in
matter.
– Electricity
– Magnetism
– Light (includes invisible
light such as ultraviolet,
infrared, etc.)
Chemical Energy
• Energy that comes from
forming or breaking
bonds
– Signs of a chemical reaction
– Batteries
– Airbags
Transformations of Energy
DEMONSTRATION
•Potassium Permanganate + Glycerine = Surprise FIRE!
•List the energy transformations.
Time for a Lab!
• Transformations of Energy Lab
The Law of Conservation of Energy
• Energy cannot be created or destroyed, but it can
be transformed.
• Sound familiar? What does this remind you of….?
Pendulum Demonstration
Newton’s Cradle Demonstration
Time for a Lab!
• Basketball Blaster Lab