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7.P.2.1 (Energy) C.Notes
What is energy
Ability to cause change
Types of energy
Mechanical energy – ability to do work (sum of potential & kinetic energy)
 Form of energy involved in the operation of simple machines
Potential energy – stored energy in an object due to its position (energy at rest)
Kinetic energy – energy in motion
 Amount of kinetic energy depends on mass & speed
Electrical energy - energy carried by electric current
 Natural forms (green energy): lightning, solar energy, water power, wind power
o Doesn’t create extra pollutants
Geothermal energy – form of heat energy generated inside Earth
Hydroelectric energy – potential energy of water transformed into electrical energy
 Energy is created by dams
Chemical energy – energy stored in chemical bonds between atoms
 Food you eat has stored chemical energy
Light energy – energy carried by light and other kinds of electromagnetic waves
 Can be absorbed, reflected or transmitted
Thermal energy – energy that comes from heat
 Warmer substance is , more thermal energy
 Can be transferred by conduction, convection & radiation
Solar energy – limitless energy source from the sun
Sound energy - energy made by vibrations that travel in waves
Energy transfers from one system
to another
Thermally – warm object & cool object
 Ice cube melting
Mechanically – push or pull over distance
Electrically – when an electrical source such as a battery or generator is connected in a
complete circuit to an electrical device
Electromagnetic waves – caused by the vibration of an electric charge
 Waves seen after an explosion
**when energy transfers from one system to another, HEAT is ALWAYS involved**
Batteries – store energy and transfer energy to components in a circuit
 Energy comes from chemical reactions
Electricity – important because it is used for so many things
 To produce electricity, a heat source is ALWAYS required
o Methods to produce electricity: burning of fossil fuels, water power, wind
power
Mechanical energy


Potential (PE) vs. Kinetic Energy
(KE)
7.P.2.1 (Energy) C.Notes
Objects with mechanical energy are able to do work
Energy involved with operation of simple machines
Potential Energy
Energy at rest
Doesn’t use energy until it moves
Kinetic Energy
Energy in motion
Conservation of Energy
Energy cannot be created nor destroyed
 Energy only changes forms
Different forms of energy
Motion & heat
Different ways for energy to
travel
Light, sound, electricity
Circuit
Definition - The complete path around which electric current flows
Require a complete loop through which an electrical current can pass
 Example: Charging your cell phone needs a complete loop or cell phone doesn’t
charge
Types of circuits
Series circuit - electrical circuit in which the electricity flows in one path

If there is a break in the path of electricity the entire circuit will not work
7.P.2.1 (Energy) C.Notes
Parallel circuit - electrical circuit in which the electricity flows in more than one direction

A break in one branch will not affect the other branches or appliances
Describe mechanical energy
Kinetic vs. potential energy  transfer (explain, illustrate (video)
Various forms of energy
Ways energy travels
Cosmos video  Energy
Circuits/batteries
7.P.2.1 (Energy) C.Notes