TemperatureMicroscopic AtomsMacroscopic PropertiesHot and ColdThermal ContactThermal EquilibriumLaw ZeroGas ThermometerKelvinTemperature ScalesBody TemperatureTemperatureTemperatureMicroscopic AtomsMicroscopic AtomsSolidSolid•Atoms vibrate Atoms vibrate in a nearly in a nearly fixed positionfixed positionGasGas•Atoms apart, Atoms apart, freely moving in freely moving in the volumethe volumeLiquidLiquid•Atoms close, Atoms close, but free to but free to move aroundmove aroundAtoms in matter are in constant motion.Atoms in matter are in constant motion.Interaction of atoms determines the state of matter.Interaction of atoms determines the state of matter.Macroscopic PropertiesMacroscopic PropertiesThere are about 5 x 10There are about 5 x 102424 atoms in a golf ball. atoms in a golf ball. We track its motion as a We track its motion as a whole, not as atoms.whole, not as atoms.Density and pressure apply Density and pressure apply to the whole object, not the to the whole object, not the atoms.atoms.These are macroscopic These are macroscopic properties.properties.Microscopic properties:mass, position, velocity, energyMacroscopic properties:mass, position, velocity, energyanddensity, pressure, temperatureHot and ColdHot and ColdTemperature is a Temperature is a macroscopic property of macroscopic property of matter.matter.•Based on statisticsBased on statistics•Doesn’t generally apply to Doesn’t generally apply to single atomssingle atomsHot matter has more energy Hot matter has more energy per atom on average than per atom on average than cold matter.cold matter.•Single atoms may have less Single atoms may have less energy in a hot itemenergy in a hot itemThermal ContactThermal ContactTwo cups of water are in Two cups of water are in contact.contact.•Heat one cupHeat one cup•Compare macroscopic Compare macroscopic propertiespropertiesIf they are the same they are If they are the same they are in thermal contact.in thermal contact.•eg. metal cupseg. metal cupsIf different they are insulated.If different they are insulated.heaterheaterThermal EquilibriumThermal EquilibriumTwo systems have the same temperature if they are Two systems have the same temperature if they are in thermal equilibrium.in thermal equilibrium.•Equilibrium between systemsEquilibrium between systems•Measure of macroscopic propertiesMeasure of macroscopic propertiesIf two systems are not in thermodynamic equilibrium, If two systems are not in thermodynamic equilibrium, they are not in thermal contact.they are not in thermal contact.Law ZeroLaw ZeroIf two systems are each in thermodynamic If two systems are each in thermodynamic equilibrium with a third system, then they are in equilibrium with a third system, then they are in thermodynamic equilibrium with each other.thermodynamic equilibrium with each other.This is the Zeroth Law of Thermodynamics.This is the Zeroth Law of Thermodynamics.A B CA is in thermal equilibrium with B.C is in thermal equilibrium with B.Therefore, A is in thermal equilibrium with C.Gas ThermometerGas ThermometerA system with known macroscopic properties may be A system with known macroscopic properties may be placed in thermodynamic equilibrium.placed in thermodynamic equilibrium.A device that uses this is a A device that uses this is a thermometerthermometer..This thermometer uses the pressure of gas in a bulb.The meter measures the height in a manometer or barometer.KelvinKelvinTemperature requires a Temperature requires a scale to compare different scale to compare different systems.systems.The Kelvin (K) is the SI unit The Kelvin (K) is the SI unit of temperature.of temperature.•Based on behavior of waterBased on behavior of water•Linear pressure scaleLinear pressure scale•NotNot degreesdegrees Kelvin Kelvin1010-4-4 K KSuperfluid liquid heliumSuperfluid liquid helium4 K4 KHelium boilsHelium boils77 K77 KAir boilsAir boils273 K273 KWater meltsWater melts373 K373 KWater boilsWater boils630 K630 KMercury boilsMercury boils1000 K1000 KCopper meltsCopper melts6000 K6000 KSurface of the sunSurface of the sun101066 K KSolar coronaSolar corona101088 K KHydrogen bombHydrogen bomb316.273PPT Temperature ScalesTemperature ScalesFor everyday temperatures For everyday temperatures the Celsius scale (the Celsius scale (C) is C) is used.used.Each Each C is the same C is the same magnitude as 1 K.magnitude as 1 K.•The zero is differentThe zero is different•0 0 C = 273.15 KC = 273.15 K•Not quite T at PNot quite T at P33The English system uses the The English system uses the Fahrenheit scale (Fahrenheit scale (F).F).Ice point at 1 atm is 32Ice point at 1 atm is 32..Boiling point at 1 atm is 212Boiling point at 1 atm is 212..Each Each F is 5/9 of a F is 5/9 of a C.C.3259CFTTBody TemperatureBody TemperatureNormal body temperature is Normal body temperature is 98.6 98.6 F. What is the F. What is the equivalent in equivalent in C and K?C and K?If your fever is 101.6 If your fever is 101.6 F, by F, by how much has it risen in how much has it risen in C C and K?and K?The general formula applies The general formula applies for a conversion between for a conversion between scales.scales.•TTCC = (5/9)( = (5/9)(TTFF – 32) – 32)•(5/9)(98.6 – 32.0) = 37.0 (5/9)(98.6 – 32.0) = 37.0 CC•TT = = TTCC + 273.15 = 310.2 K + 273.15 = 310.2 KThe difference use the The difference use the fractional change.fractional change.• TTCC = (5/9) = (5/9) TTFF •(5/9)(101.6 – 98.6) = 1.7 (5/9)(101.6 – 98.6) = 1.7 CC• TT = = TTCC = 1.7 K= 1.7
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