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Law of conservation of energy Definitions Energy Kinetic energy Potential energy Law of conservation of energy
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What do all of these things have in common?
They are types of energy Law of conservation of energy
Definitions Energy Kinetic energy Potential energy Law of
conservation ofenergy Warm Up #1 What is the energy possessed
bymatter due to its motion called? What are the two main types
ofenergy? Give unique examples of the two maintypes of energy. Look
at your activity from yesterday. Did it follow the law of
conservation ofenergy?What is your evidence? Mechanical Energy
Definition Kinetic energy how do you increase?
Faster Larger objects (moremass) Potential energy how do you
increase? Put more in the bank Mechanical Energy Kinetic Wind
Electricity Radiant or Light Potential Chemical Nuclear Thermal
Conservation of Energy
Cant create or destroy energy Total is the same Ski hill Energy at
the top Energy in the middle Energy at the bottom Changes Energy
Forms Happens in all changes Spreads out
Makes thingsmore chaotic Think of yourlocker or room Warm Up #2
Video What are the major types of energy ofthe following before the
collision andafter? Balloon Water Person What other types of energy
areprobably present? Mechanical Waves Transfers energy through a
medium Medium Types
Definition Examples Types Transverse Longitudinal How the matter
moves Parts of a Transverse Wave Speed of Waves Speed = frequency x
wavelength v = fl
Speed (m/s) Wavelength (m) Frequency (Hertz = Hz = cycles/second)
Find the speed of a wave if it has a frequencyof 5 Hz and a
wavelength of 12m. A wave is traveling with a speed of 224m/s.What
is the frequency of this wave given itswavelength is 37 m? Given
the frequency is 110Hz and the speedis 1500 m/s, what is the
wavelength? Energy in Waves Which set of hills takes more energy to
run?
High energy Short wavelength High frequency Large amplitude Clicker
Quiz Warm-Up #3 Take the paper clip and unfold it
Then bend it back and forth over in the same location several times
Place the point where you are bending it on your lips What do you
observe? What conclusions can you make from your observations and
what we have learned in class? Electromagnetic Wave Definition
Electromagnetic spectrum
Travel at the speed of light (3x108 m/s) Vary in wavelength and
frequency Uses Radio Microwave Infrared Visible Ultraviolet X-ray
Gamma
Really Muscular Idiots
Visualize Ultra X-treme Grannies Heat Thermal energy - definition
Heat - definition Beaker example
Flows from high temp. to low temp. Beaker example Compare
temperature Compare thermal energy How would heat move? (A to B or
B to A) Heat = energy transferred between objects that have
different temperatures; matter doesnt contain heat, matter contains
thermal energy and transfers that energy which is heat Thermal
energy will be transferred from the high temp. object to the low
temp. object until thermal equilibrium is reached which is when all
the objects have the same amount of thermal energy and generally
the same temperature In the beakers: the temperatures are equal at
100oC, there is more thermal energy in beaker A because there are
more molecules so there is a higher total KE Cold really is the
lack of thermal energy; so really we have high or low thermal
energy Beaker A 100oC 100 mL Beaker B 100oC 50 mL How is Thermal
Energy Transferred?
Conduction Direct contact Collisions Changes High temp. to low
temp. Conduction is one way that thermal energy can be transferred
it requires the two objects to be touching each other, the faster
molecules in one object collide with the slower molecules of the
other and transfer KE which causes the slower molecules to speed up
(increase temp.) Energy is always transferred from high temp. to
low temp. = 2nd law of thermodynamics Conductors substances that
transfer energy well, metals are good conductors Insulators
substance that are poor at transferring energy; fiberglass, water,
paper are good insulators and poor conductors Convection Movement
in liquid or gas Hot liquids
Less dense Rise Collides with slower, cooler liquid More dense
Sinks Reheated near source Process repeats Currents Oceans
Atmosphere Convection: transfer of thermal energy through motion of
a gas or liquid As a liquid is heated it becomes less dense as the
molecules speed up and spread out and less dense things will rise
As the warmer liquid rises it collides with cooler and slower
moving molecules and transfers energy to those molecules making the
original molecules to lose energy and become a cooler temperature
and more dense and thus sink As the liquid/gas gets near the heat
source, the process begins again This creates currents of upward
and downward moving water/air This happens in the ocean and the
atmosphere (creates thermals that you see birds soaring on but
staying in about the same place) Radiation Definition Examples Car
on cold day T-shirt on sunny day
Greenhouse effect Heat transfer by light waves (electromagnetic
radiation, so more than just visible light) Car on cold day or
t-shirt on a sunny day can get really warm depending on the color
even warmer than the air surrounding it This occurs greenhouse
effect where light enters the atmosphere and is absorbed by objects
which increases the temperature of the object and then heat is
transferred to the atmosphere and can be held in by the gases
(carbon dioxide, methane and water vapor) in the atmosphere
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