1. Work, Energy, and Power

2. Work (W) The product of the force (F) applied to an object over a distance (d) in which the object travels as a result of the force Joule (j) is the base unit of work (Force and distance must be parallel to each other)

3. A student lifts a 50 pound (lb) ball 4 feet (ft) in 5 seconds (s). How many joules of work has the student completed? Convert English units to SI units Solve for Work Work Example

4. Energy Ability to do work ( light, heat, mechanical, chemical, electrical) NASA solar sail Fuel cell Roller coaster

5. Forms of Energy Potential Energy (Stored energy or gravitational energy) The capacity to do work by virtue of position or configuration

6. Forms of Energy Kinetic Energy (Energy of motion) Energy which a body possesses because of its motion, which occurs anywhere from an atomic level to that of a whole organism

7. Energy Transformation Chemical Radiant Electrical

8. Renewable Energy SourcesBiomass Hydropowe Hydropower Geothermal Wind Solar

9. Nonrenewable Energy SourcesPetroleum Natural Gas Coal Uranium

10. Conservation of Energy Energy cannot be created or destroyed, but it can change from one form to another. Energy Efficiency: The ratio of the useful energy delivered by a dynamic system to the energy supplied to it Entropy: The loss of energy during conversion Energy Conversion Changing one form of energy to another

11. Energy Conversion Examples Fossil fuels Chemical → Heat → Mechanical → Electrical Solar cells Sunlight → Electrical Wind turbines Kinetic → Mechanical → Electrical Hydroelectric Gravitational potential → Mechanical → Electrical Nuclear Nuclear → Heat → Mechanical → Electrical Vehicle System Conversion Chemical Mechanical Heat Which output is desired, mechanical or heat?

12. What Are Current Energy Concerns? Consumption What roles do engineers have in energy? PollutionDepletionDependencyCost http://www.eia.doe.gov

13. Power Rate at which work is performed or energy is expended Watt is the base unit of Power One watt is equal to 1 joule of work per second

14. Types of Power Electrical Power Uses electrical energy to do work Mechanical Power Uses mechanical energy to do work (linear, rotary) Fluid Power Uses energy transferred by liquids (hydraulic) and gases (pneumatic)

15. Power Example Power = Work / Time Work = 271.45J A student lifts a 50.0 pound (lb) ball 4.00 feet (ft) in 5.00seconds (s). How many watts of power are used to lift the ball?