{"id":109728,"date":"2015-08-03T03:00:00","date_gmt":"2015-08-03T00:00:00","guid":{"rendered":"http:\/\/www.fyysika.ee\/?guid=6564d2eee8eb0a406ea90e5586578609"},"modified":"2015-08-03T03:00:00","modified_gmt":"2015-08-03T00:00:00","slug":"the-frictionless-damping-of-a-piston-in-thermodynamics","status":"publish","type":"post","link":"https:\/\/www.fyysika.ee\/?p=109728","title":{"rendered":"The frictionless damping of a piston in thermodynamics"},"content":{"rendered":"<p>The paper revisits R\u00fcchardt\u2019s experiment and the two-chamber variant of Clark and Katz, where the<br \/>\noscillating motion of a freely sliding piston involves the adiabatic exponent of the gas enclosed in<br \/>\na thermally isolated chamber. While the common theoretical account of the experiment correctly<br \/>\npredicts the frequency of the oscillation, the damping is usually ascribed to a linear frictional<br \/>\nforce of an undetermined mechanical nature. In this paper, we argue that the irreversibility of the<br \/>\ndamped motion calls for a thermodynamical treatment involving dissipation (entropy production). The<br \/>\ntheory of R\u00fcchardt\u2019s experiment is reworked at the undergraduate level by allowing entropy to change<br \/>\nowing to heat transfer into or out of the chamber. It is calculated that a linear heat transfer can<br \/>\nexplain the observed damping without assuming any mechanical friction. The calculation is<br \/>\nquantitatively supported by an experiment. It is also calculated that the mechanical and thermal<br \/>\nequilibrations&#8230;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The paper revisits R\u00fcchardt\u2019s experiment and the two-chamber variant of Clark and Katz, where the<br \/>\noscillating motion of a freely sliding piston involves the adiabatic exponent of the gas enclosed in<br \/>\na thermally isolated chamber. While the common t&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[178],"tags":[],"class_list":{"0":"post-109728","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-rss-fuusikaharidus","7":"entry"},"_links":{"self":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/109728","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=109728"}],"version-history":[{"count":0,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/109728\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=109728"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=109728"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=109728"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}