P OTENTIAL E NERGY

P OTENTIAL VS. K INETIC  Potential Energy – the energy of position  An object is not moving or doing work  Kinetic Energy – the energy of motion  The faster an object moves, the more kinetic energy it has

P OTENTIAL E NERGY  Potential Energy is a type of energy that is “hidden” in some way.  Potential Energy can be converted to other forms of energy and often is related to some attractive or pushing forces.

F ORMS OF P OTENTIAL E NERGY  5 Forms of Potential Energy 1. Gravitational Potential Energy 2. Elastic Potential Energy 3. Chemical Potential Energy 4. Electrical Potential Energy 5. Magnetic Potential Energy

G RAVITATIONAL P OTENTIAL E NERGY  There is a constant attractive force between the Earth and everything surrounding it, due to gravity.

G RAVITATIONAL P OTENTIAL E NERGY  Gravitational Potential Energy: Potential energy that is dependent on the height above the Earth’s surface and the mass of the object

G RAVITATIONAL P OTENTIAL E NERGY  The higher the position above the surface or a reference point, the greater the gravitational potential energy

G RAVITATIONAL P OTENTIAL E NERGY  The greater the mass, the greater the gravitational potential energy

G RAVITATIONAL P OTENTIAL E NERGY  Example: In the diagram the water in the reservoir represents gravitational potential energy because the height of the water will be used to increase the kinetic energy needed to move the turbine

G RAVITATIONAL P OTENTIAL E NERGY  A change in the height of an object is evidence that the gravitational potential energy has changed.

E LASTIC P OTENTIAL E NERGY  Elastic Potential Energy: Potential energy associated with how much an elastic object has been stretched or compressed and how difficult such a compression or stretch is.

E LASTIC P OTENTIAL E NERGY  Anything that can act like a spring or a rubberband can have elastic potential energy.

E LASTIC P OTENTIAL E NERGY  Example: When you stretch a rubberband it has stored energy – it is ready to do work. When you release the rubberband, the energy is converted into kinetic energy, or the energy of motion.

E LASTIC P OTENTIAL E NERGY  A change in the amount of compression or stretch of an elastic object is evidence that the elastic potential energy has changed.

C HEMICAL P OTENTIAL E NERGY  Chemical Potential Energy: Potential energy associated with the position and arrangement of the atoms within substances.

C HEMICAL P OTENTIAL E NERGY  Rearranging atoms into new positions to form new substances (chemical reaction) is evidence that the chemical potential energy has most likely changed.

C HEMICAL P OTENTIAL E NERGY  The energy transferred when a chemical system undergoes a reaction is often thermal energy.

E LECTRICAL P OTENTIAL E NERGY  Electrical Potential Energy: Potential energy associated with the position of electrically charged objects relative to each other and the amount of charge they have.

 Example: If you push a large boulder up to the top of a cliff, you are gaining gravitational potential energy the further you get from Earth’s surface. Similarly, the further a charge gets from the electrical field the more electrical potential energy it has.

E LECTRICAL P OTENTIAL E NERGY  A change in the position of charged particles relative to each other is evidence of a change in electrical potential energy.

M AGNETIC P OTENTIAL E NERGY  Magnetic Potential Energy: Potential energy associated with the position of magnetic objects relative to each other.

M AGNETIC P OTENTIAL E NERGY  If the opposite poles are held apart, the potential energy will be the highest when they are near the edge of their attraction, and the lowest when they pull together.

M AGNETIC P OTENTIAL E NERGY  Conversely, like poles will have the highest potential energy when forced together, and the lowest when they spring apart.