Energy NOTES
Energy – the ability to do WORK
Energy is a property of matter (all matter has energy)
*It is easier to describe what energy does than
what energy is*
Law of Conservation of Energy –
States that energy can be transferred from one
object to another, but energy cannot be created
or destroyed.
Forms of ENERGY
1. Mechanical Energy – energy an object has
because of its motion or position
a) Kinetic Energy – energy of motion
(the greater the speed and mass the greater
the kinetic energy
b) Potential Energy – energy of position
(stored energy)
-gravitational = stored energy due to height
- elastic = stored energy due to stretching or compressing
- chemical = stored energy in the chemical bonds of matter
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Gravitational potential energy
Elastic potential energy
Chemical potential energy
Examples of Potential
and Kinetic Energy
being Transferred
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Forms of ENERGY
2. Thermal Energy – the energy
related to the temperature of a
substance (heat energy)
Temperature vs. Heat
Temperature = a measure of the average
kinetic energy of the particles in a
substance.
Heat = the transfer of thermal energy
between substances from the warmer
substance to the cooler substance
Thermometer =
measures
temperature
* Heat flows from a warmer substance to a cooler
substance.
Methods of Heat Transfer
A. Conduction = transfer of heat by direct contact.
Heat from the end
of the metal rod
travels to the hand
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B. Convection = transfer of heat in a fluid
through currents. (Heat rises)
C. Radiation = transfer of energy as
electromagnetic waves.
*Can travel through empty space as well as
through solids, liquids, and gases.
through empty space
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Examples of heat transfer
Forms of ENERGY
3. Light Energy – the energy carried by light and
other kinds of electromagnetic waves
Properties of light
•Light spreads out in all
directions from its source.
•Light travels in straight lines
called rays.
Decreasing wavelength
Increasing frequency
•Light travels “at the speed
of light”
186,282 miles per second
•Light can travel in a
vacuum (empty space) as
well as through matter.
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Forms of ENERGY
4. Sound Energy – the energy carried by sound waves
Sound is produced when an object vibrates.
The vibrating object pushes the particles of matter next to it and
causes them to compress (squeeze together). The
compressed matter squeezes the matter next to it. The
compression travels through the matter as a wave of energy.
Sound waves travel in all directions away from their source.
Sound travels more slowly than light. (761 miles per hour)
Sound waves must travel through a medium. (solid, liquid, or gas)
Forms of ENERGY
5. Chemical Energy – the energy stored in
chemical bonds
gasoline
food
battery
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Forms of ENERGY
6. Electrical Energy – the energy produced
by electric charges
Forms of ENERGY
7. Nuclear Energy – the energy contained
in the nuclei of atoms
Nuclear Power Plant
Nuclear Fission = splitting atoms to produce ENERGY
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