Download Forms of Energy

Unit 3
Lesson 4
Forms of Energy
S8.C.2.1.1
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Forms of Energy
1.
Mechanical Energy – is the total potential and kinetic energy of
an object
• PE + KE = ME
Potential Energy- energy stored in an object because of its position or
shape
• Gravitational potential energy- stored energy because of
position (Bike on top of a hill) GPE= weight x height
• Elastic potential energy - stored energy because an object
is stretched, bent, or compressed beyond its natural shape
(stretched rubber band)
Kinetic Energy- energy of motion. Energy of moving objects
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Depends on mass and speed of the object
More massive and faster moving objects have more kinetic
energy
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Kinetic vs Potential
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Kinetic vs Potential
Skate park
Oh no!....not again
Video clip
Video clip- swing
Quiz
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Forms of Energy
2. Thermal Energy – (Heat)
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energy that flows from warm
objects to cooler objects
When you heat matter, the
particles move faster so fast
moving particles bump
slower moving particles,
making them move faster
also
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Food coloring ex.
Ice cube example
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Forms of Energy
3. Chemical Energy – energy stored in the
chemical bonds of molecules and
compounds (Think: food, batteries and
fuels including fossil fuels and wood)
1. Food contains molecules of fats, proteins, and carbohydrates
2. Fossil Fuels were formed from the remains of living things
which are made of molecules which contain chemical energy
**When the chemical bonds of these molecules break during
chemical reactions, chemical energy is released**
3. Batteries are made of chemical molecules which react and
produce electrical energy as a result
• Zinc Chloride (ZnCl2), Ammonium Chloride (NH4Cl), Magnesium Dioxide (MgO2) 7
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Chemical Molecules in Fossil Fuels
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Forms of Energy
4. Nuclear Energy- Energy stored
in the nucleus of an atom
which holds the protons and
neutrons together
•When nuclei are split apart or
combine, they release nuclear
energy
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Forms of Energy
5. Electrical Energy – Energy of
moving electrons
- The flow of electrons
Examples:
Lightening
Electricity
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Forms of Energy
6. Sound Energy – produced by vibrating objects
• Sound Waves can only travel through matter
• The molecules aren't moving across the room.
They just get bumped, and they bump the ones
next to them.
Speed of sound
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7. Light Energy
• Also called Radiant Energy or
Electromagnetic Radiation or
EM Energy
• Waves that travel through
matter and/or empty space
(vacuum of space)
• Don’t need a medium (matter) to
travel through like a sound wave
does
• Energy in the form of a wave
that comes from stars (suns) in
space
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7 Types of Light Energy (EM Radiation):
All come from Stars (Suns)
All travel at speed of light
1. Gamma Rays- used for cancer treatment
2. X-Rays- pass through soft tissue (skin) and are absorbed
by hard tissue (bone)
3. UV Rays- We don’t feel these. Gives us a sunburn. Also
used in fluorescent bulbs
4. Visible/White Light- We can detect with eyes if it
reflects off something
5. Infrared- felt as heat- heat transferred through radiation
6. Microwaves- cell phone communication, microwave
ovens for cooking, and radar detection
7. Radio Waves- communication ( broadcasting) with TV
and radio
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Wavelength vs Frequency
Wavelength- the length of a wave
Frequency- how often a wave occurs
*Inverse/ Indirect
Relationship
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Electromagnetic Spectrum
ROYGBIV
10,000 m
10-14 m
Long wavelength
Short wavelength
Low Frequency
High Frequency
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Speed of Light
** All 7 forms of EM energy travel at the SOL
Speed of light = approx. 670 million mph (186,000 miles per second)
Speed of Sound = approx. 760 mph in air (faster in liquid and solids)
• Energy from our Sun takes about 8 minutes
to reach Earth
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Speed of Light
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670 million mph
186,000 miles/sec
300,000 km/sec
300 million meters/sec
7 x around Earth in a second
In the vacuum
of space
• SOL in air is slower than in a vacuum. Air is made of gas
molecules which slow light down as it passes through them.
• The more dense the substance, the slower light travels through
it. (OPPOSITE OF SOUND)
Vacuum = 186,000 miles/sec
Air
= 185,400 miles/sec
Water
= 140,000 miles/sec
Glass
= 124,000 miles/sec
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Light Year
• The distance light (energy) will
travel in a year if uninterrupted
• About 6 trillion miles
• Not a Time Period
• If a star is 5 light years away, it
will take its energy 5 years to
get here
• Some stars are billions of light
years away! Space is infinitely
big!
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