{"id":3220,"date":"2026-10-11T17:26:48","date_gmt":"2026-10-11T04:26:48","guid":{"rendered":"https:\/\/iypt.org.nz\/?page_id=3220"},"modified":"2026-10-12T21:32:39","modified_gmt":"2026-10-12T08:32:39","slug":"problem-7-cold-drink","status":"publish","type":"page","link":"https:\/\/iypt.org.nz\/?page_id=3220","title":{"rendered":"Problem 7: Cold Drink"},"content":{"rendered":"\n<p class=\"has-text-align-center has-x-large-font-size wp-block-paragraph\">How cold can you get a bottle or can of drink with ice and salt?           And how fast?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is a simplified version of the full problem that only considers using salt and ice. The full problem can be extended to include forms of non-consumable alcohol, e.g. some hand sanitisers.<\/p>\n\n\n\n<div style=\"height:35px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Problem in full<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This is problem 15 of 17 for IYPT 2027<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>&#8220;A can or bottle of drink at room temperature can be cooled in a cooler containing ice. Adding salt and alcohol to the ice can increase the rate of cooling and affect the drink\u2019s final temperature. Investigate how the relevant parameters affect the lowest achievable temperature and the maximum cooling rate.&#8221;<\/em><\/p>\n\n\n\n<div style=\"height:35px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Specialist Equipment<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A thermometer that can measure temperatures below 0\u00b0C.<\/li>\n\n\n\n<li>A thermometer that can measure the temperature of an object in water.<\/li>\n\n\n\n<li>Safe, secure storage for any alcohol used.<\/li>\n\n\n\n<li>Most non-cosumable alcohol is poisonous. DO NOT DRINK IT. <strong>IT COULD KILL YOU.<\/strong><\/li>\n<\/ul>\n\n\n\n<div style=\"height:35px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Safety first<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Use gloves or cloths to carry extremely cold items.<\/li>\n\n\n\n<li>Do not drink the liquid in the can or bottle (if it is drinkable) until it has warmed up to safe temperature.<\/li>\n\n\n\n<li>Do not consume any alcohol used!<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>How cold can you get a bottle or can of drink with ice and salt? And how fast? This is a simplified version of the full problem that only considers using salt and ice. The full problem can be extended to include forms of non-consumable alcohol, e.g. some hand sanitisers. Problem in full This is [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":3223,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-3220","page","type-page","status-publish","has-post-thumbnail","hentry"],"_links":{"self":[{"href":"https:\/\/iypt.org.nz\/index.php?rest_route=\/wp\/v2\/pages\/3220","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iypt.org.nz\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/iypt.org.nz\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/iypt.org.nz\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/iypt.org.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3220"}],"version-history":[{"count":5,"href":"https:\/\/iypt.org.nz\/index.php?rest_route=\/wp\/v2\/pages\/3220\/revisions"}],"predecessor-version":[{"id":3327,"href":"https:\/\/iypt.org.nz\/index.php?rest_route=\/wp\/v2\/pages\/3220\/revisions\/3327"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/iypt.org.nz\/index.php?rest_route=\/wp\/v2\/media\/3223"}],"wp:attachment":[{"href":"https:\/\/iypt.org.nz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}