3 Energy is the ability to work. NOTESEnergy is the ability to work.Work is done when a force exerted on an object moves that object some distance.Work is a transfer of energy
4 Units are: Newtons x meters Both work and energy are measured in joules.Work & energy is force times distanceUnits are: Newtons x metersorJoules
5 Two Types of Energy Kinetic Energy Energy associated with motion Ex. Dropping the bowling ball.Potential EnergyStored energyEx. Lifting a bowling ball to a height.
6 Kinetic Energy= 1/2mass X velocity squared Kinetic Energy = ½m x v²
7 = JKE = (½ 3600Kg) X (10m/s)²Kinetic energy depends on the square velocity! So at twice the speed the truck has 4 x the energyIf the truck has a mass of 3,600Kg and a velocity of 10m/s, what’s it’s Kinetic energy?A more massive truck has more kinetic energy.
8 Equation for Gravitational Potential energy PEgrav = mass x gravity x heightorPEgrav = m x g x h
13 Gravitational Potential Energy 50Kg10 meters highPEgrav = mass x gravity x height= 4900JPEgrav = 50Kg x 9.8m/s/s x 10m
14 Now calculate Kinetic Energy 50KgNow calculate Kinetic EnergyWhat’s its velocity if it falls for one second?Kinetic Energy = ½m x v²= 2401 JKE = (½ 50Kg) X (9.8m/s)²
15 Energy conversion – a change from one form of energy to another form.
16 Energy conversion cont… Most forms of energy can be converted into other formsExample: Mechanical energy (running water) can be converted into electrical energy (electricity)
17 For example burning coal at an electrical power plant converts chemical energy into heat. The heat makes steam which turns turbines mechanical energy to make electrical energy. The electrical energy is converted back into heat (oven), light (lights in the house), and mechanical energy (a car’s engine) when it is used.Gas enginephotosynthesisFood your bodyHeat lamp or hair dryerOil electricity via power plant
21 Different Forms of Energy Mechanical = motion or position of an objectThermal = total energy of the particles in an object (the more energy the more heat is given off)Chemical = PE stored in chemical bonds (food)
22 Electrical = energy caused by moving electric charges
23 Electromagnetic energy = visible light, microwaves, x-rays, and uv light
31 Common Types of Fossil Fuels CoalOil (petroleum)Natural Gas
32 Fossil Fuels make good fuels because the energy stored in them is abundant and easy to release when heated.Methane CH4 (gas)Ethane C2H6 (gas)Propane C3H8 (gas)Butane C4H10 (gas)Pentane C5H12 (liquid, found in gasoline)Hexane C6H14 (liquid, found in gasoline)Heptane C7H16 (liquid, found in gasoline)Octane C8H18 (liquid, found in gasoline)Pentadecane C15H32 (liquid, found in kerosene and jet fuel)Tetracosane C24H50 (liquid, found in lubricating oil)
33 Some common uses of Crude Oil SolventsFertilizersPesticidesPlasticsDiesel fuelJet fuelliquified petroleum gasplasticsKeroseneSynthetic fibersSynthetic rubberDetergents