1. Energy - The Ability To Cause Change -

2. Kinetic Energy  energy due to motion  Kinetic Energy and Speed  the faster an object moves, the more kinetic energy it has  Kinetic Energy and Mass  objects with more mass have more kinetic energy

3. Potential Energy  stored energy due to the interactions between objects or particles  There are 3 Types of Potential Energy: 1. Gravitational Potential Energy - energy stored between an object and the Earth  depends on the object’s weight and height

4. Potential Energy 2. Elastic Potential Energy – energy stored in objects that are compressed or stretched  ex. rubber bands, springs 3. Chemical Potential Energy – energy stored in the chemical bonds between atoms; released during chemical reactions  ex. food, gasoline

5. Forms of Energy Form of EnergyDefinitionExample Mechanical Energysum of kinetic and potential energies in a system of objects shooting a basketball Sound Energyenergy that sound carriesvibrating objects Thermal Energysum of kinetic and potential energies of particles that make up an object heat warmer  cooler Electric Energyenergy an electric current carriesappliances Radiant/Light Energyenergy carried by electromagnetic waves light, microwaves, x-rays Nuclear Energyenergy stored and released in the nucleus of atoms uranium in nuclear power plants

6. Energy Transformations

7. Transforming Energy  Examples:  microwave oven (electrical  radiant  thermal)  photosynthesis (radiant  chemical)  digestion (chemical  mechanical)

8. Throwing a Ball Into the Air  Kinetic Energy to Potential Energy  kinetic energy is greatest when you first throw it  kinetic energy decreases, but potential energy increases as the ball rises  Potential Energy to Kinetic Energy  potential energy is greatest as the ball reaches its highest point  potential energy decreases, but kinetic energy increases as the ball falls back down

9. The Law of Conservation of Energy  energy can be transformed from one form into another, but energy cannot be created or destroyed  Friction – a force that resists the sliding of two surfaces that are touching  transforms mechanical energy into thermal energy  decrease friction by using lubricants (ex. oil, grease)

10. Waste Energy  Thermal energy that is “lost” or cannot be used during a transformation  Examples:  Light Bulb (electrical  radiant and thermal)  Cars (chemical  mechanical and thermal)

11. Make Some Transformations  List the energy transformations in these objects:  Hair Dryer  Solar-powered Calculator  Flashlight

12. Make Some Transformations  List the energy transformations in these objects:  Hair Dryer  (electrical  thermal and sound)  Solar-powered Calculator  (radiant  electrical  radiant and thermal)  Flashlight  (chemical  electrical  radiant and thermal)