{"id":443645,"date":"2017-08-31T02:00:00","date_gmt":"2017-08-30T23:00:00","guid":{"rendered":"http:\/\/www.fyysika.ee\/?guid=01263b3c7d7418e71e517d420f88990b"},"modified":"2017-08-31T02:00:00","modified_gmt":"2017-08-30T23:00:00","slug":"free-fall-and-the-equivalence-principle-revisited","status":"publish","type":"post","link":"https:\/\/www.fyysika.ee\/?p=443645","title":{"rendered":"Free fall and the equivalence principle revisited"},"content":{"rendered":"<p>Free fall is commonly discussed as an example of the equivalence principle, in the context of a<br \/>\nhomogeneous gravitational field, which is a reasonable approximation for small test masses falling<br \/>\nmoderate distances. Newton\u2019s law of gravity provides a generalisation to larger distances, and also<br \/>\nbrings in an inhomogeneity in the gravitational field. In addition, Newton\u2019s third law of action and<br \/>\nreaction causes the Earth to accelerate towards the falling object, bringing in a mass dependence in<br \/>\nthe time required for an object to reach ground\u2014in spite of the equivalence between inertial and<br \/>\ngravitational mass. These aspects are rarely discussed in textbooks when the motion of everyday<br \/>\nobjects are discussed. Although these effects are extremely small, it may still be important for<br \/>\nteachers to make assumptions and approximations explicit, to be aware of small corrections, and also<br \/>\nto be prepared to estimate their size. Even if the corrections are not part of regular teaching,<br \/>\nsome stu&#8230;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Free fall is commonly discussed as an example of the equivalence principle, in the context of a<br \/>\nhomogeneous gravitational field, which is a reasonable approximation for small test masses falling<br \/>\nmoderate distances. Newton\u2019s law of gravity provides &#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-443645","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\/443645","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=443645"}],"version-history":[{"count":0,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/443645\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=443645"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=443645"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=443645"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}