Conservation of EnergyEnergy can be neither created nor destroyedEnergy is conservedEnergy can be transferred between different formsAs an object falls, its potential energy is transferred to kinetic energyWhen the object stops, the kinetic energy is transferred to heatTemperatureTemperature is a measure of the average speed of the molecules of a substanceSome molecules move faster, other molecules move slowerWhen the molecules within an object absorb energy, they move fasterThe temperature of the object increasesMore energetic collisions between moleculesTemperature and densityWarm air is less dense (prone to rise)Cold air is more dense (prone to sink)Rising Air and TemperatureThink of a blob of air the size of this roomThis is called an air parcelAs a hot air parcel rises, the pressure around it decreases, so the air parcel expandsPressure ALWAYS decreases with heightIt requires energy for an air parcel to expandWhere does this energy come from?The temperature of the parcel cools as it expandsSummary: Hot (less dense) air rises, expands, and coolsSinking Air and TemperatureAs an air parcel sinks, the pressure around it increases, so the air parcel is compressedPressure always increases as you go down toward the surfaceCompression transfers energy to the parcelSinking air compresses and warmsHeat EnergySensible heat: Heat that can be sensed or measured with a thermometerLatent heat: The energy absorbed or released during a phase change“Hidden” energySolar Heating: Sun heats the surface which then heats the airAir is largely transparent to sunlightClear sky=transparentHazy sky= not transparentSun does not heat the air directlyThe sun heats the surfaceThin layer of air (1 cm or so) just above surface is heated by conductionRight next to the hot groundThis hot air expands, becomes less dense, and begins to riseHot, less dense air rises, like helium balloonsThis rising air transports heat upward from the surface (convection)The troposphere is heated from the bottom up!Blobs (parcels) of hot air rise, like helium balloonsTransport heat upward from the surface (convection)Cooler air from aloft sinks and is later heated by surface..Heat TransferConduction: Direct transfer of heat within a substance (or from one substance to another)Ex. Touching a hot stove and burning yourselfHeat always flows from hot to coldGood heat conductors transfer heat eddicientlyEx. MetalsPoor heat conductors (good insulators)Ex. Air, water, wood, plastic, fiberglassConvection: Transfer of heat through fluid flowGenerally refers to vertical motions onlyAir and water are both fluidsAdvection: Transfer of heat (or moisture) through horizontal movements of airEx. Cool breeze brom the sea or lazePhase ChangesOn earth, water exists naturally in all three phases: Solid, liquid, and gasIce (solid)Water (liquid)Water vapor (gas)Deposition (warming): gassolidSublimation (cooling): solidgasFreezing (warming): liquidsolidMelting (cooling): solidliquidCondensation (warming): gasliquidWarming process releases latent heat into the environmentAmount of energy absorbed during evaporation=energy released during condensationLatent heat released via condensation powers many weather systemsEx. A single thunderstorm releases several times more energy in one hour via condensation than the atomic bomb dropped on Hiroshima in 1945. A thunderstorm releases its energy over a much larger area and much slower than a bomb, though so that is why cities are not destroyed by thunderstorms.Evaporation (cooling): liquidgasCooling process absorbs latent heat from environmentEx. This is why you feel cold after getting out of the shower or swimming poolEnergy, Temperature, and Heat 09/10/2012Conservation of Energy-Energy can be neither created nor destroyedoEnergy is conserved-Energy can be transferred between different formsoAs an object falls, its potential energy is transferred to kinetic energy-When the object stops, the kinetic energy is transferred to heatTemperature-Temperature is a measure of the average speed of the molecules of a substanceoSome molecules move faster, other molecules move slower-When the molecules within an object absorb energy, they move fasteroThe temperature of the object increasesoMore energetic collisions between molecules-Temperature and densityoWarm air is less dense (prone to rise) oCold air is more dense (prone to sink)-Rising Air and TemperatureoThink of a blob of air the size of this roomThis is called an air parceloAs a hot air parcel rises, the pressure around it decreases, so the airparcel expandsPressure ALWAYS decreases with heightoIt requires energy for an air parcel to expandWhere does this energy come from?The temperature of the parcel cools as it expandsoSummary: Hot (less dense) air rises, expands, and cools-Sinking Air and TemperatureoAs an air parcel sinks, the pressure around it increases, so the air parcel is compressedPressure always increases as you go down toward the surfaceoCompression transfers energy to the parceloSinking air compresses and warmsHeat Energy-Sensible heat: Heat that can be sensed or measured with a thermometer-Latent heat: The energy absorbed or released during a phase changeo“Hidden” energy-Solar Heating: Sun heats the surface which then heats the airoAir is largely transparent to sunlightClear sky=transparentHazy sky= not transparent oSun does not heat the air directlyoThe sun heats the surfaceoThin layer of air (1 cm or so) just above surface is heated by conductionRight next to the hot groundoThis hot air expands, becomes less dense, and begins to riseHot, less dense air rises, like helium balloonsThis rising air transports heat upward from the surface (convection)oThe troposphere is heated from the bottom up!oBlobs (parcels) of hot air rise, like helium balloonsTransport heat upward from the surface (convection)oCooler air from aloft sinks and is later heated by surface..Heat Transfer-Conduction: Direct transfer of heat within a substance (or from one substance to another)oEx. Touching a hot stove and burning yourselfoHeat always flows from hot to coldoGood heat conductors transfer heat eddicientlyEx. MetalsoPoor heat conductors (good insulators)Ex. Air, water, wood, plastic, fiberglass-Convection: Transfer of heat through fluid flowoGenerally refers to vertical motions onlyoAir and water are both fluids-Advection: Transfer of heat (or moisture) through