{"id":458,"date":"2020-04-16T21:18:48","date_gmt":"2020-04-16T21:18:48","guid":{"rendered":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/?page_id=458"},"modified":"2026-05-11T06:09:15","modified_gmt":"2026-05-11T06:09:15","slug":"popcan","status":"publish","type":"page","link":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/exhibits\/em\/popcan\/","title":{"rendered":"Pop Can"},"content":{"rendered":"

Pop Can<\/h1>\n\n\n
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\"\"<\/figure>\n<\/div>\n\n\n\n
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\"\"<\/figure>\n<\/div>\n<\/div>\n\n\n\n
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In this exhibit, we can see the mystery of the rotating pop can that act at a distance.<\/p>\n\n\n\n

To begin press the bottom “START”. Use the aluminum bar to cover 2\/3 of the surface of the magnet pole face and observe as the can begins to rotate.<\/p>\n\n\n\n

 <\/p>\n\n\n\n

NOW AN EXPLANATION ON HOW THIS WORKS<\/strong><\/p>\n\n\n\n

 <\/p>\n\n\n\n

1-<\/strong> The magnet produces an alternating magnetic field<\/p>\n\n\n\n

2-<\/strong> Initially the rising magnetic field from the magnet induces currents in metallic objects (the can and the aluminum bar).<\/p>\n\n\n\n

3-<\/strong> These currents generate magnetic fields in the opposite direction so that the objects are repelled.<\/p>\n\n\n\n

 <\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

4- <\/strong> Next, when the field reaches its maximum value, its rate of change becomes zero. The induced field becomes also zero.<\/p>\n\n\n\n

5-<\/strong> The can becomes quickly demagnetized because it is thin.<\/p>\n\n\n\n

6-<\/strong> But the current in the thicker aluminum bar continues longer, so the aluminum bar remains magnetized for a little while.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

7- <\/strong> Next the field of the magnet begins decreasing; it induces a field in the opposite direction. The can gets magnetized the new way, but the aluminum bar retains the \u201cold\u201d magnetization and attracts the magnetized can.<\/p>\n\n\n\n

8- <\/strong> Voila! rotation begins<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

You can try changing the position of the aluminum bar<\/p>\n\n\n\n

You can also try using other metal sheets from the table.<\/p>\n\n\n\n

 <\/p>\n\n\n\n

Physics Lecture Demonstration Database<\/a> <\/b><\/i><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

In this exhibit, we can see the mystery of the rotating pop can that act at a distance. To begin press the bottom “START”. Use the aluminum bar to cover 2\/3 of the surface of the magnet pole face and observe as the can begins to rotate.   NOW AN EXPLANATION ON HOW THIS WORKS …<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":63,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uw_migration_status":"complete","_uw_gutenberg_post_content_before_migration":"","_uw_seo_meta_title":"","_uw_seo_meta_description":"","_uw_seo_twitter_card_type":"","_uw_seo_meta_image":"","_uw_seo_meta_image_url":"","_uw_seo_meta_image_sizes":[],"_uw_seo_custom_meta_tags":[],"footnotes":""},"class_list":["post-458","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/pages\/458","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/comments?post=458"}],"version-history":[{"count":4,"href":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/pages\/458\/revisions"}],"predecessor-version":[{"id":959,"href":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/pages\/458\/revisions\/959"}],"up":[{"embeddable":true,"href":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/pages\/63"}],"wp:attachment":[{"href":"https:\/\/wp.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/media?parent=458"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}