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phy131studiof15:lectures:chapter19 [2015/11/06 08:50] mdawber [Thermal Expansion] |
phy131studiof15:lectures:chapter19 [2015/11/11 08:54] mdawber [Using the Ideal Gas Law to determine Absolute Zero] |
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===== 19.P.014 ===== | ===== 19.P.014 ===== | ||

+ | ===== 19.P.017 ===== | ||

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These stresses can be reduced by the inclusion of [[wp>Expansion_joint|expansion joints]] in bridges, roads and pipes. | These stresses can be reduced by the inclusion of [[wp>Expansion_joint|expansion joints]] in bridges, roads and pipes. | ||

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+ | ===== 19.P.025 ===== | ||

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===== What makes a gas ideal?===== | ===== What makes a gas ideal?===== | ||

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This equation is the [[wp>Ideal_gas_law|ideal gas law]] | This equation is the [[wp>Ideal_gas_law|ideal gas law]] | ||

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+ | ===== 19.P.034 ===== | ||

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+ | ===== 19.P.042 ===== | ||

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+ | ===== 19.P.044 ===== | ||

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===== Ideal Gas Law for a number of molecules ===== | ===== Ideal Gas Law for a number of molecules ===== | ||

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===== Using the Ideal Gas Law to determine Absolute Zero ===== | ===== Using the Ideal Gas Law to determine Absolute Zero ===== | ||

- | If $PV=nRT$ the absolute zero temperature occurs when $P=0$. In practice most gases will liquefy before this point, but we can measure the pressure of fixed volume of gas at a couple of reference points and extrapolate down to zero pressure to get an estimate for [[wp>Absolute_zero|absolute zero]]. | + | If $PV=nRT$ the absolute zero temperature occurs when $P=0$. In practice most gases will liquefy before this point, but we can measure the pressure of a fixed volume of gas at a couple of reference points and extrapolate down to zero pressure to get an estimate for [[wp>Absolute_zero|absolute zero]]. |

Through laser cooling and molecular trapping techniques it is now possible (but difficult!) for temperatures on the order of a $\mathrm{nK}$ to be achieved. Prof. [[http://ultracold.physics.sunysb.edu/index.html|Dominik Schneble]] produces ultra-cold ($\mu K$) Bose-Einstein condensates in the basement of this building! Prof. [[http://www.stonybrook.edu/metcalf/hmetcalf.html|Hal Metcalf]] was one of the key players in the original development of laser cooling. | Through laser cooling and molecular trapping techniques it is now possible (but difficult!) for temperatures on the order of a $\mathrm{nK}$ to be achieved. Prof. [[http://ultracold.physics.sunysb.edu/index.html|Dominik Schneble]] produces ultra-cold ($\mu K$) Bose-Einstein condensates in the basement of this building! Prof. [[http://www.stonybrook.edu/metcalf/hmetcalf.html|Hal Metcalf]] was one of the key players in the original development of laser cooling. | ||