Types Of Energy

Types of Energy The Law of Conservation of Energy Magnetism & Electricity Conservation of Energy Types of Energy Transfer Energy & Work Simple Machines

Heat energy Heat energy is the transfer of thermal energy(associated with the motion) All matter is made up of particles too small tobe seen.

Heat energy As heat energy is added to a substance, thetemperature goes up indicating that the particlesare moving faster. The faster the particles move,the higher the temperature. Sources of heat energy: burning material, thesun, and electricityHeated Solid Animation

Solar energy Solar energy is the energy from the Sun, which providesheat and light energy for Earth. Solar cells can be used to convert solar energy to electricalenergy. Green plants use solar energyduring photosynthesis to producesugar, which contains storedchemical energy. Most of the energy that we useon Earth originally came from theSun.

Chemical energy Chemical energy is energystored in particles of matter. Chemical energy can bereleased, for example inbatteries or sugar/food, whenthese particles react to formnew substances.

Electrical energy Electrical energy is theenergy flowing in anelectric circuit. Sources of electricalenergy include: storedchemical energy inbatteries; solar energyin solar cells; fuels orhydroelectric energy ingenerators.

Mechanical energy Mechanical energy is theenergy due to the motion(kinetic) and position(potential) of an object.When objects are set inmotion or are in a positionwhere they can be set inmotion, they havemechanical energy.

Mechanical Potential energy: Potential energy is storedenergy. Mechanical potential energy is related to theposition of an object. Examples: A stretched rubber band,and water behind a dam

Mechanical Kinetic energy: Kinetic energy is theenergy an object has due to its motion. Mechanicalkinetic energy increases as an object movesfaster. Example: a moving car

States that energy cannot be created or destroyed. It maybe transformed from one form into another, but the totalamount of energy never changes. Examples of potentialkinetic mechanicaltransformations might include:Potential EnergyWater behind a damKinetic EnergyWater flowing over a damStretched rubber bandBook resting on shelf(position)Released rubber bandBook falling from shelf

Energy transformations may involve other kinds of energy.ExampleEnergy TransformationsBook fallingKineticsound, heatWater moving over damKineticelectrical (viagenerator)Green plantsSolarstored chemical(sugar)Animals eating foodChemicalkinetic (moving)Burning carbon-basedfuelChemicalheat energy,electricalElectrical circuit(using an outlet)electricalmechanical, heat, sound,and lightThe total amount of energy is conserved.

Magnetism is the force ofattraction or repulsion ofmagnetic materials. Surrounding a magnet is amagnetic field that applies aforce, a push or pull, withoutactually touching an object. An electric current flowingthrough a wire wrappedaround an iron core forms amagnet.

Electromagnets An electromagnet is formedwhen a wire in an electriccircuit is wrapped around aniron core producing amagnetic field. The magnet that resultsloses its magnetism if theelectric current stopsflowing.

Generators A generatorproduces an electriccurrent when a coil ofwire wrapped aroundan iron core is rotatednear a magnet. Generators at powerplants produceelectric energy for ourhomes.

A generator containscoils of wire that arestationary, and rotatingmagnets are rotated byturbines. Turbines arehuge wheels that rotatewhen pushed by water,wind, or steam. Thus mechanical energy is changed to electricalenergy by a generator. Smaller generators may bepowered by gasoline.

Simple electric motors· An electric motorchanges electrical energyto mechanical energy.· It contains anelectromagnet that rotatesbetween the poles of amagnet.· The coil of theelectromagnet isconnected to a battery orother source of electriccurrent.

· When an electric currentflows through the wire in theelectromagnet, a magneticfield is produced in the coil.· Like poles of the magnetsrepel and unlike poles of themagnets attract.· This causes the coil torotate and thus changeselectrical energy tomechanical energy.· This rotating coil of wire canbe attached to a shaft and ablade in an electric fan.

electrical energy can betransformed to light, sound,heat, and mechanical motion inan electric circuit. An electric circuit contains asource of electrical energy, aconductor of the electricalenergy (wire) connected to theenergy source, and a devicethat uses and transforms theelectrical energy.Electricity Link

All thesecomponentsmust beconnected in acomplete,unbroken path inorder for energytransformationsto occur.

The electrical energy in circuits may come from manysources including:SourceBatterySolar cellElectricaloutletsEnergy comes from Stored chemical energyLight energy from sunChemical energy (burningfuels)Most electricity is produced by coal-burning power plantsbut can also be provided by using nuclear energy,hydroelectric energy, and geothermal power plants.

Electrical energy can be transformed to other forms ofenergy in a circuit.Devices used inelectrical circuitEnergy TransformationsLight: Light bulb chemical (battery)electricallight &heatSound: buzzer,radio, tvchemical (battery)electricalsoundHeat: toaster,stove, or heaterChemical (fuel)heatgenerator)electricalMechanical(kinetic): fan,motorChemical (battery)mechanical (to turn aheat (used in device)electricalmechanical

Conduction, Convection & RadiationConductioninvolves objects indirect contact. The transfer ofenergy as heatoccurs betweenparticles as theycollide within asubstance orbetween twoobjects in contact.

Conduction, Convection & Radiation All materials do not conduct heat energy equally well. Poor conductors of heat are called insulators. The energy transfers from an area of highertemperature to an area of lower temperature.

For example, if a plastic spoon and a metal spoonare placed into a hot liquid, the handle of themetal spoon will get hot quicker than the handle ofthe plastic spoon because the heat is conductedthrough the metal spoon better than through theplastic spoon.

Convection is the transfer of energy as heat by movementof the heated substance itself, as currents in fluids (liquidsand gases). In convection, particles with higher energy move from onelocation to another carrying their energy with them.

Heat transfer occurs when particleswith higher energy move from warmerto cooler parts of the fluid. Uneven heating can resultin convection, both in the airand in water. This causescurrents in the atmosphere(wind) and in bodies of wateron earth which are importantFactors in weather andclimate.

Radiation is the transfer ofenergy through space withoutparticles of matter colliding ormoving to transfer the energy. This radiated energy warmsan object when it is absorbed. Radiant heat energy movesfrom an area of highertemperature to an area ofcooler temperature.

Energy is a property that enables somethingto do work. Work means to (1) apply a force to an objectover a distance, and (2) the object moves inresponse to the force. If something has the ability to cause a change inmotion, it is has energy. Energy can cause work to be done, so when wesee work done, we see evidence of energy.

Evidence of energy is when work is being done.For example: When a toy car at rest is pushed, work is doneon the car if it moves. This work (or movement)is evidence of energy. When a fan is connected to an electric circuit, itmoves, so work was done on the fan. This work(or movement) is evidence of energy. When an object is lifted, it moves, so work isdone on the object. This work (or movement) isevidence of energy.

A spring scale isused to measureforce. Force(including weight) ismeasured in SI unitscalled newtons (N).

A simple machine is a device that helps reduce theamount of force required to do work. Work is donewhen a force (effort force) is applied over a distance. A simple machine allows the user to apply a smallerforce over a larger distance to move an object. Simple machines can also change the direction of theforce applied. If the distance over which the effort force is exerted isincreased, the same amount of work can be done witha smaller effort force.EdHeads Simple Machine Website

Lever- is a rigid bar or board thatis free to move around a fixedpoint called a fulcrum. The fulcrum may be placed atdifferent locations along the bar. A lever can reduce the amount offorce required to lift a weight intwo ways:Lever AnimationsThe Lever Story

By increasing the distance from the fulcrum to thepoint where the effort force is applied, or bydecreasing the distance the weight is from thefulcrum.

By increasing the distance the effort forcemoves relative to the distance the weight moves,a lever can reduce the effort force needed.

ARCHIMEDESArchimedes (287-212 BC) was an ancient Greek mathematician.Among his many accomplishments was the first description of thelever (around 260 BC). Levers are one of the basic tools. Many ofour basic tools use levers: including scissors (two class-1 levers),pliers (two class-1 levers), hammer claws (one class-1 lever),nutcrackers (two class-2 levers), and tongs (two class-3 levers).

Pulley- has a grooved wheel with a rope running along thegroove. change the amount and/or the direction of the effort force. if you increase the distance that the effort force moves relativeto the distance the weight moves, a pulley can reduce the effortforce needed. movable pulleys reduce the effort force. a single fixed pulley changes only the direction of the force(you pull down and the weight goes up.)Pulley Animations

PulleysFixed pulleys, thoseattached to a structure, canbe found on the top of a flagpole and on window blinds.Moveable pulleys, those notattached to a structure, canbe found on constructioncranes and as part of a blockand tackle system.Pulley System InteractiveThe Pulley Story

Inclined plane- is a sloping surface, likea ramp, that reduces the amount of forcerequired to lift an object. An inclined plane can reduce the forceneeded to lift a weight in two ways:(1) increase the length of the ramp or (2)decrease the height of the ramp. By increasing the distance the effortforce moves (length of the ramp) relativeto the distance the weight is lifted (heightof the ramp), an inclined plane canreduce the effort force needed.

Inclined planes- with a sloping surface can be found asramps on a truck or wheelchair ramp and stairs.Inclined planes that are wedges, one inclined plane or twoback-to-back inclined planes that can move are found asknife blades or nails.Inclined planes that are wound around a post or cylinderare called screws. Screws can be found in bolts and jarlids.

Wheel and axles- consist of two circular objects: acentral shaft, called an axle, inserted through themiddle of a wheel.Wheel and axles can be found as door knobs,steering wheels, screwdrivers, gears, and bicycleswheels.

Complex machines- also known as compoundmachines consist of two or more simple machines.Examples include: scissors consisting of two levers and two inclinedplanes (wedges); a fishing pole consisting of a lever, a wheel and axleand a pulley; a bicycle consists of levers (handlebars andhandbrakes), wheel and axles (gears, wheels, andpedals), and a number of screws.EdHeads Compound Machines Website

The force applied to the lever (thecrowbar) makes the rock move andthe work easier to do.A wheelbarrow is one example of acompound machine. It has twolevers (the handles) to help lift theload, and a wheel and axle to make iteasier to move the load forward.

An inclined plane is a flat surfacethat is at an angle to the load. Thistype of ‘machine’ has no parts thatmove.The direction of the force is alsobeing changed by the lever.Pushing down on the lever (thescrewdriver) raises the load (thepaint can lid).