Transcript Transformations and Conservation of energyx

Energy Transformation
Notes
Describe the
energy forms
involved in baking a
cake.
Daily Objectives
• Describe how different forms of energy are
related.
• Explain common energy transformations.
• Apply the Law of Conservation of Energy
Energy Transformations
• A change from one energy form to another.
– EX: Toaster – Electrical to
Thermal (Heats your toast)
Electromagnetic (Light you see)
– EX: Mechanical energy to strike a match creates thermal energy, which
releases the chemical energy in the match, which makes more thermal
energy (burning of the match) and electromagnetic energy (light you see)
Chemical Energy –
stored in match
Thermal - Heat
Electromagnetic
- Light
Law of Conservation of Energy
• Energy Cannot be Created NOR Destroyed!
– When one form of energy transforms into another, no energy is
destroyed in the process.
– The total amount of energy before and after remains the same.
• Mechanical Energy = G. Potential + Kinetic
– the total amount of Mechanical Energy remains the same – is
conserved.
Think about it
• In real life, it may seem like energy is being lost
sometimes (you slow down, a pendulum doesn’t go
on forever).
• Where does this energy go if it isn’t being destroyed?
Einstein
• Matter is anything that has mass and takes up space. All
objects are made of matter.
• Einstein discovered that matter can be transformed into energy and
energy into matter.
• Is this a violation of the law of conservation of energy?
• Can you think of a cool application of this discovery (what
could scientists potentially do with this ability?)
Perpetual Motion Machine? – Think
about it…
• Perpetual motion machine - a device that creates
its own power and can therefore run forever.
• Explain these in terms of the Law of
Conservation of Energy..
Mechanical Energy and Conservation
• The total Mechanical Energy of an object must
remain the same
• Energy can change from Gravitational
Potential to Kinetic and Back
– The total remains the same (assuming no friction)
Mechanical Energy
Watch how the Law of Energy Conservation
works on a rollercoaster!
http://ca.pbslearningmedia.org/resource/hew0
6.sci.phys.maf.rollercoaster/energy-in-a-rollercoaster-ride/
Review of Daily Objectives
• Explain the energy transformations involved in
turning on a light?
• How is energy conserved when it changes
from potential to kinetic when a bicyclist rides
down a hill?