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What is energy?
Energy is the ability to do work, or Energy is the ability to do work, or cause change. Energy is literally cause change. Energy is literally what makes the world and what makes the world and everything in it everything in it gogo. Energy is the . Energy is the magicmagic stuff stored in the battery stuff stored in the battery that makes the flashlight work. The that makes the flashlight work. The gasoline in a car’s gas tank gasoline in a car’s gas tank contains energy. The car’s engine contains energy. The car’s engine merely converts the gasoline’s merely converts the gasoline’s energy into a usable form.energy into a usable form.
While there are many forms While there are many forms
and sources of energy,and sources of energy, there are only two types:there are only two types:
Potential
Kinetic
Kinetic ““energy associated with energy associated with
motion.”motion.”
When discussing kinetic energy, it’s When discussing kinetic energy, it’s important to keep in mind that the mass andimportant to keep in mind that the mass and velocity of an object determine its kinetic velocity of an object determine its kinetic energy. We can take a look at kinetic energy energy. We can take a look at kinetic energy by throwing a basketball and a baseball. by throwing a basketball and a baseball.
Potential““The energy something has which is The energy something has which is
stored and not moving.”stored and not moving.” ““the energy that a piece of matter has because of the energy that a piece of matter has because of
its position or because of the arrangement of its position or because of the arrangement of parts” because the matter has the potential, or parts” because the matter has the potential, or opportunity, to do work. opportunity, to do work.
There are two types of potential energy: elastic There are two types of potential energy: elastic potential energy and gravitational potential potential energy and gravitational potential energy. energy.
Water behind a dam has gravitational potential Water behind a dam has gravitational potential energy.energy.
A stretched rubber band has elastic potentialA stretched rubber band has elastic potential
Forms of energy Mechanical — the energy of motion Mechanical — the energy of motion Electrical — think lightning or electricity moving Electrical — think lightning or electricity moving
through electrical wires through electrical wires Electromagnetic or radiant — energy of Electromagnetic or radiant — energy of
magnetism and light magnetism and light Chemical — energy produced by chemical Chemical — energy produced by chemical
reactions like those that occur in batteries reactions like those that occur in batteries Nuclear — potential energy stored in the nuclei of Nuclear — potential energy stored in the nuclei of
atoms atoms
Sound — the energy of vibratingSound — the energy of vibrating sound waves sound waves Heat – from burning fuel or the earthHeat – from burning fuel or the earth
Energy Conversion
Many of the devices we use Many of the devices we use every day convert energy from every day convert energy from one form to another.one form to another.
These devices are called These devices are called transducers.transducers.
Transducers
Flashlight — converts Flashlight — converts chemical energy (stored in chemical energy (stored in the battery) to electrical the battery) to electrical energy to light the bulb. energy to light the bulb.
The bulb converts the The bulb converts the electrical energy to electrical energy to electromagnetic or electromagnetic or
radiant energy.radiant energy.
Transducers
Toaster — converts electrical Toaster — converts electrical energy into thermal energy. energy into thermal energy.
Transducers
Car engine — converts the Car engine — converts the chemical energy stored in the chemical energy stored in the gasoline into mechanical and gasoline into mechanical and thermal energy.thermal energy.
Practical ways to produce electricity
Generator - - - - > MechanicalBattery - - - - - > ChemicalPhotovoltaic cell - - - - - > Light(solar cell)Piezio Electric (crystals) - - - - - > Pressure
Generator – A mechanical device that Generator – A mechanical device that produces electricity by a process of rotating produces electricity by a process of rotating a magnet inside a coil of copper wire. A a magnet inside a coil of copper wire. A generator is a transducer that uses rotary generator is a transducer that uses rotary mechanical motion to produces electricity. mechanical motion to produces electricity.
Natural Energy All Renewable All Renewable
Non Consumed when usedNon Consumed when used
SolarSolar
WindWind
WaterWater
GeothermalGeothermal
Energy Existing in Nature
Natural energy sources are Natural energy sources are ALL RENEWABLEALL RENEWABLE
Heat Energy
Geothermal – heat from the earthGeothermal – heat from the earth
Solar Thermal – heat from the sunSolar Thermal – heat from the sun
Solar Energy
Light energy --Light energy -- Electrical energy Electrical energy
Uses Photovoltaic CellUses Photovoltaic Cell
Water must be Moving•Hydroelectric Power- dams & rivers•Tidal – vertical movement of tides•Wave – using the up/down motion of
waves•Thermal-using the temperature difference
of oceans
Water Energy
Fuels
AdvantagesAdvantages PortablePortable StorableStorable
DisadvantagesDisadvantages PollutePollute
Energy from Fuels
Must Be Burned to Create SteamMust Be Burned to Create Steam PollutePollute
Some are :Some are : RenewableRenewable Non RenewableNon Renewable
Renewable Fuels
Replaceable in a short period of timeReplaceable in a short period of time Biomass - - - - -> Once aliveBiomass - - - - -> Once alive PlantsPlants
Trees-WoodTrees-Wood Corn,Sugar Cane – AlcoholCorn,Sugar Cane – Alcohol
GarbageGarbage
Non Renewable Fuels
Fossil FuelsFossil Fuels Petroleum- OilPetroleum- Oil
GasolineGasolineHeating OilHeating OilPlasticsPlastics
CoalCoal Natural GasNatural Gas
Non Renewable Energy
Nuclear Nuclear Fission - split atomsFission - split atoms Fusion – combine atomsFusion – combine atoms
Energy Conservation
Shut off lightsShut off lights Fluorescent/Compact lightsFluorescent/Compact lights