2Standard III: Physical Sciences BenchmarksStandard III: Physical SciencesE. Demonstrate that energy can be considered to be either kinetic (motion) or potential (stored).F. Explain how energy may change form of be redistributed but the total quantity of energy is conserved.G. Demonstrate that waves have energy and waves can transfer energy when they interact with matter.H. Trace the historical development of scientific theories and ideas, and describe emerging issues in the study of physical sciences.
3-Complete Calculating Work Practice sheet What is Energy?Energy - ability to do workWork - force moves an object a distanceW = Fdunits are Joules ( J ) for energyunits for force are Newtons ( N )units for distance are meters ( m )*** A Joule can also be considered a “Nm”-Complete Calculating Work Practice sheet
4States of EnergyPotential Energy - stored energy, based on position of chemical compositionGravitational Potential EnergyGPE = mass x gravity x heightGPE = mgh --> units Joulesm=mass (g) g=gravity (9.8 m/s2) h=height (m)A 50kg rock is on the edge of a 20m cliff, what is its GPE?GPE = m x g x h= 50kg x 9.8m/s2 x 20m = 9800J
5States of Energy the Sequel Kinetic Energy - energy of motion, based on mass and velocity of objectKinetic EnergyKE = 1/2 mv2 --> units Joulesm=mass (g) v=velocity (m/s)A 1000kg car is traveling 40m/s, what is its KE?KE = 1/2mv2= 1/2 x 100kg x (40m/s)2= 1/2 x 100kg x 1600m2/s2 = 80,000J-Complete Calculating Power and Potential/Kinetic Energy worksheets
6Forms of Energy Six Forms of Energy Mechanical - moving objects perform workEx: wheels turning, hammer hitting a nail, soundChemical - energy stored in the molecules of substancesEx: coal, oil, nature gas, foodNuclear Energy - stored in nucleus of atomEx: Uranium used for fission
7Forms of Energy Six Forms of Energy 4. Heat - energy caused by molecular motionEx: Rubbing hands together, lighting a match5. Electrical - flow of electrons through a conductorEx: computers, televisions, generators6. Light - radiant energy that moves in wavesEx: sun, light bulbs, electromagnetic energy
8Conservation of Energy and Matter The Law of Conservation of Energyenergy can be neither created nor destroyed, only transformedThe Law of Conservation of Mattermatter can be neither created nor destroyed, only rearranged*The total amount of matter and energy in the always remains constant in the universe
9Types of Energy RENEWABLE Solar – energy harnessed from the sun Hydroelectric– energy harnessed from the Potential energy of waterBiomass– energy harnessed agricultural and animal waste productsWind– energy harnessed from the windGeothermal– energy harnessed from heat under earth’s crust
10NONRENEWABLE Fossil fuels: energy from natural gas, petroleum and coal Nuclear: energy from fission and fusionWhat are the advantages and disadvantages of each?Energy brochure: what type of energy do you think Ohio should consider to help our energy demands and decrease our dependence on coal.
11Energy Transformations Energy can transform from one form to anotherEx: A black car absorbs light energy from the sun and transforms it to heat energy to warm up the car***During many energy transformations heat is produced as an unwanted productEx: Motors loose a great deal of energy to unwanted heat energy-%efficiency worksheet
12Nuclear Energy The three categories of forces are: Gravitational ForcesElectromagnetic ForcesNuclear Forces1. Strong Force2. Weak Force*Nuclear forces are the strongest types
13FissionFission is the process of splitting the nucleus of an atom into two lighter weight nuclei producing large amounts of energyBombarding Ur-235 or Pu with a neutron causes it to split into Kr and Ba, and continues as a chain reactionUsed in nuclear power plants and weaponsProduces nuclear waste
14FusionFusion is the process of combining two or more lighter weight nuclei to form a heavier nucleus releasing large amounts of energyHydrogen isotopes are converted to Helium under extreme temperaturesDoes not produce waste products, has abundant resources (Hydrogen), and is safer than fission
15Nuclear ReactorNuclear reactors control the fission process by using the heat produced to produce steam that turns a turbine to produce electricityThe moderator and control rods slow the speed of the fission reaction by absorbing neutronsThere is lead shielding around the core to protect against radiation
16Nuclear Incidents Meltdowns: Chernobyl in Russia Recent Tsunami in JapanPartial Meltdowns:-3 mile Island (1979, Harrisburg, Pa)-experimental partial meltdowns:Fermi 1 (1966), Borax-1 (1954)