{"id":137535,"date":"2015-10-28T03:00:00","date_gmt":"2015-10-28T00:00:00","guid":{"rendered":"http:\/\/www.fyysika.ee\/?guid=324dd411baa6bde2ab6a6fa291a7de02"},"modified":"2015-10-28T03:00:00","modified_gmt":"2015-10-28T00:00:00","slug":"feynman-and-the-kinetic-energy-of-an-ice-skater","status":"publish","type":"post","link":"https:\/\/www.fyysika.ee\/?p=137535","title":{"rendered":"Feynman and the kinetic energy of an ice skater"},"content":{"rendered":"<p>By employing the angular momentum and mechanical energy theorems, we analyse the increase of the<br \/>\nangular velocity for an ice skater who changes his arms, initially in an horizontal position, along<br \/>\nthe axis of the body, first with respect to the lab frame, in which a variation of kinetic energy is<br \/>\nobserved, and then with respect to the rotating frame moving with the skater. In the last one, while<br \/>\nthere is no variation of kinetic energy between initial and final positions, the work of the<br \/>\ncentrifugal force is the opposite to the variation of kinetic energy in the lab frame. We discuss<br \/>\nthe explanation given by Richard Feynman in his Mechanics course.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>By employing the angular momentum and mechanical energy theorems, we analyse the increase of the<br \/>\nangular velocity for an ice skater who changes his arms, initially in an horizontal position, along<br \/>\nthe axis of the body, first with respect to the lab f&#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-137535","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\/137535","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=137535"}],"version-history":[{"count":0,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/137535\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=137535"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=137535"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=137535"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}