{"id":2732,"date":"2017-09-12T20:02:40","date_gmt":"2017-09-13T03:02:40","guid":{"rendered":""},"modified":"2026-01-21T12:36:48","modified_gmt":"2026-01-21T20:36:48","slug":"2732","status":"publish","type":"post","link":"https:\/\/www.vernier.com\/til\/2732","title":{"rendered":"What are the moments of inertia of the disks included in the Rotary Motion Accessory Kit?"},"content":{"rendered":"<p>The <a href=\"\/product\/rotational-motion-accessory-kit\/\">Rotational Motion Accessory Kit<\/a> (<nobr>AK-RMV<\/nobr>) includes several discs for rotary motion experiments.<\/p>\n<ul class=\"wp-block-list\">\n<li>Smooth discs: <strong>1.05 x 10<sup>-4<\/sup> kg m<sup>2<\/sup><\/strong><br \/>Typical dimensions and masses<br \/>\u25b8The disc with a small hole: 106 g, 89.0 mm diameter, 3.6 mm hole<br \/>\u25b8The disc with cork and a larger hole: 106 g, 89.0 mm diameter, 6.0 mm hole<\/li>\n<\/ul>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<ul class=\"wp-block-list\">\n<li>Heavy washer: <strong>2.86 x 10<sup>-4<\/sup> kg m<sup>2<\/sup><\/strong> (approximate, as dimensions and mass vary)<br \/>Our sample&#8217;s dimensions and mass<br \/>\u25b8 270 g, 88.5 mm diameter, 27 mm diameter inner hole<\/li>\n<\/ul>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<ul class=\"wp-block-list\">\n<li>Metal rod: <strong>4.93 x 10<sup>-4<\/sup> kg m<sup>2<\/sup><\/strong> (when rotated about its center)<br \/>Typical dimensions and mass<br \/>\u25b841 g, 38 cm length<\/li>\n<\/ul>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<ul class=\"wp-block-list\">\n<li>Plastic disk: <strong>5 x 10<sup>-7<\/sup> kg m<sup>2<\/sup><\/strong> (insert for washer)<br \/>Typical dimensions and mass<br \/>\u25b84.5 g in mass, 27 mm diameter, 3.6 mm hole<\/li>\n<\/ul>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<ul class=\"wp-block-list\">\n<li>3-step pulley: <strong>2 x 10<sup>-6<\/sup> kg m<sup>2<\/sup><\/strong><br \/>See also <a href=\"\/til\/1012\/\">What are the dimensions of the 3-step pulley\/wheel on the Rotary Motion Sensor?<\/a>.<\/li>\n<\/ul>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<ul class=\"wp-block-list\">\n<li>(2) Round masses at ends of rod: <strong>5.68 x 10<sup>-3<\/sup> kg m<sup>2<\/sup><\/strong><br \/>Typical mass<br \/>41 g in mass<\/li>\n<\/ul>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<p><strong>Notes: <\/strong><br \/>\u25cf In comparison to the metal disks, the plastic parts have negligible moments and can be disregarded.<br \/>\u25cf Masses will vary. For most accurate calculations, determine the mass independently.<br \/>\u25cf In early editions, experiment 14 of the <a href=\"\/product\/advanced-physics-with-vernier-mechanics\/\"><i>Advanced Physics with Vernier &mdash; Mechanics<\/i><\/a> (<nobr>PHYS-AM<\/nobr>) book incorrectly listed the value for the Moment of inertia as 100 times too large.<br \/>\u25cf The screw that attaches to the rod\/tip of the sensor is 6-32 threading<br \/>\u25cf The swivel mount that attaches to the back of the sensor 1\/4-20 threading.<\/p>\n<p><a href=\"\/til\/1439\/\">Rotary Motion Sensor Troubleshooting and FAQs<\/a><br \/><a href=\"\/til\/4051\/\">Go Direct Rotary Motion Troubleshooting and FAQs<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>The includes several discs for rotary motion experiments. Notes: \u25cf In comparison to the metal disks, the plastic parts have negligible moments and can be&#8230;<\/p>\n","protected":false},"author":86433,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[],"tags":[2780,2781,4569,4025,411],"class_list":["post-2732","post","type-post","status-publish","format-standard","hentry","tag-ak-rmv","tag-gdx-rmv","tag-misprint-typo-mistake","tag-phys-am","tag-rmv-btd"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/2732","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/users\/86433"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/comments?post=2732"}],"version-history":[{"count":0,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/2732\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/media?parent=2732"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/categories?post=2732"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/tags?post=2732"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}