F OUNDATIONS OF P HYSICS Notebook Assignment #10 Energy Notes

Energy Potential Energy Gravitational Potential Energy Elastic Potential Energy Kinetic Energy Dissipated Energy Classified As Divided Into

E NERGY The ability to cause change Can be transferred from one place or object to another Can be converted from potential to kinetic or kinetic to potential Energy can not be created or destroyed. This is called the Law of Conservation of Energy.

P OTENTIAL E NERGY Stored Energy Has the potential to cause something to change, but is not currently causing a change Several different representations of potential energy. The two main categories: Gravitation and Elastic Potential Energy

G RAVITATIONAL P OTENTIAL E NERGY (GPE) Results from an object being raised up while the force of gravity acts on it. Depends on the force of gravity and how high the object is raised.

E LASTIC P OTENTIAL E NERGY (EPE) Results from an elastic material being stretched or compressed some distance. Depends on how far the elastic material is stretched / compressed and the material’s spring constant.

K INETIC E NERGY Energy of motion Depends on the speed of the object and its mass

D ISSIPATED E NERGY Energy that is converted into energy that can no longer be “used” as kinetic or potential energy. Dissipated energy usually remain in the original location or object.

E NERGY P IE C HARTS Used to illustrate conservation of energy and energy conversion The size of the pie (circle) indicates the total energy of the object(s) The size of the pie pieces (divisions in circle) illustrates the amount of each energy. Total Energy Kinetic Energy (KE) Elastic Potential Energy (EPE) Gravitational Potential Energy (GPE)

E NERGY P IE C HARTS - W ORKSHEET 1. A wind-up toy is fully wound and at rest. EPE All of the energy in the rabbit is stored in the “wound” spring

E NERGY P IE C HARTS - W ORKSHEET 2. A wind-up toy is wound up and moving across level ground. The toy is speeding up. EPE KE EPE Elastic Potential Energy is converted to Kinetic Energy

E NERGY P IE C HARTS - W ORKSHEET 3. The toy is wound up and is moving at a constant speed up an incline. EPE KE GPE Elastic Potential Energy is converted to Gravitational Potential Energy while Kinetic Energy remains constant

E NERGY P IE C HARTS - W ORKSHEET 4. The toy is wound up and moving along at a constant speed. EPE KE Diss Elastic Potential Energy is converted to Dissipated Energy while Kinetic Energy remains constant

E NERGY P IE C HARTS - W ORKSHEET 5. The toy is wound up and slowing down as it moves up an incline. EPE KE Diss Elastic Potential Energy is converted to Dissipated Energy while Kinetic Energy remains constant

E NERGY P IE C HARTS - W ORKSHEET 6. The toy is wound up and speeding up as it moves up an incline. Elastic Potential Energy is converted to Kinetic Energy and Gravitational Potential Energy EPE KE GPE KEGPE