{"id":3849,"date":"2023-06-26T09:55:14","date_gmt":"2023-06-26T07:55:14","guid":{"rendered":"https:\/\/agora.xtec.cat\/iesantonitorroja\/?p=3849"},"modified":"2023-11-05T09:05:54","modified_gmt":"2023-11-05T08:05:54","slug":"taller-de-coets-daigua","status":"publish","type":"post","link":"https:\/\/agora.xtec.cat\/iesantonitorroja\/general\/taller-de-coets-daigua\/","title":{"rendered":"Taller de coets d&#8217;aigua"},"content":{"rendered":"<ol>\n<li class=\"western\" lang=\"ca-ES\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\"><i><b>Presentaci\u00f3 i principis f\u00edsics del coet<\/b><\/i><\/span><\/span><\/li>\n<\/ol>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">El moviment dels coets i d\u2019altres aeronaus es basa en el conegut principi d\u2019acci\u00f3 \u2013 reacci\u00f3, segons el qual si una part d\u2019un objecte es accelerat en un sentit, l\u2019altra part de l\u2019objecte es mou espont\u00e0niament en sentit contrari, de manera que l\u2019efecte global sobre la totalitat de l\u2019objecte \u00e9s nul. La part que s\u2019accelera en primera inst\u00e0ncia es coneix com a propulsor, i pot ser des dels gasos despresos en la combusti\u00f3 de la p\u00f3lvora o algun altre combustible, fins a l\u2019aire (en el cas d\u2019un globus inflat i tancat que s\u2019obre de sobte) i passant per l\u2019aigua que \u00e9s el cas d\u2019aquest taller.<\/span><\/span><\/p>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Garamond, serif;\"><b><i>2. <\/i><\/b><\/span><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\"><i><b>Croquis explicatiu d\u2019un coet d\u2019aigua<\/b><\/i><\/span><\/span><\/p>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><a href=\"https:\/\/agora.xtec.cat\/iesantonitorroja\/wp-content\/uploads\/usu2639\/2023\/06\/Sin-titulo.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-3850\" src=\"https:\/\/agora.xtec.cat\/iesantonitorroja\/wp-content\/uploads\/usu2639\/2023\/06\/Sin-titulo.png\" alt=\"\" width=\"871\" height=\"571\" srcset=\"https:\/\/agora.xtec.cat\/iesantonitorroja\/wp-content\/uploads\/usu2639\/2023\/06\/Sin-titulo.png 871w, https:\/\/agora.xtec.cat\/iesantonitorroja\/wp-content\/uploads\/usu2639\/2023\/06\/Sin-titulo-300x197.png 300w, https:\/\/agora.xtec.cat\/iesantonitorroja\/wp-content\/uploads\/usu2639\/2023\/06\/Sin-titulo-768x503.png 768w\" sizes=\"auto, (max-width: 871px) 100vw, 871px\" \/><\/a>3. <span style=\"font-family: Garamond, serif;\"><i><b><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Material i subst\u00e0ncies<\/span><\/span><\/b><\/i><\/span><\/p>\n<ul>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Una botella d\u2019aigua buida de pl\u00e0stic petita (330 ml de capacitat) sense tap.<\/span><\/span><\/p>\n<\/li>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Un vas llarg, preferentment tamb\u00e9 de pl\u00e0stic dur, m\u00e9s ample que la botella.<\/span><\/span><\/p>\n<\/li>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Paper fi d\u2019assecar mans.<\/span><\/span><\/p>\n<\/li>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Un tap de goma per tapar la botella.<\/span><\/span><\/p>\n<\/li>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Una cullereta petita, mida de caf\u00e8.<\/span><\/span><\/p>\n<\/li>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Tisores.<\/span><\/span><\/p>\n<\/li>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Un cron\u00f2metre i una calculadora.<\/span><\/span><\/p>\n<\/li>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Magn\u00e8sia efervescent, del tipus comercial <i>\u201cSal de Fruta <\/i><i><b>ENO<\/b><\/i><i>\u201d<\/i> (es pot comprar a la farm\u00e0cia).<\/span><\/span><\/p>\n<\/li>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Aigua de l\u2019aixeta.<\/span><\/span><\/p>\n<\/li>\n<\/ul>\n<p>4. <span style=\"font-family: Garamond, serif;\"><i><b><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">Procediment<\/span><\/span><\/b><\/i><\/span><\/p>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\"> Ompliu la botella amb una quarta part, aproximadament, d\u2019aigua de l\u2019aixeta. Talleu un rectangle de paper d\u2019assecar mans de dimensions suficients perqu\u00e8 es pugui enfonsar a trav\u00e9s del coll de la botella fins a formar un petit receptacle al seu interior, i que els extrems del rectangle s\u2019enganxin al coll de la botella, per la seva part exterior. Ompliu el receptacle de magn\u00e8sia efervescent, aproximadament, de 4 a 5 culleradetes de caf\u00e8, i tapeu la botella amb el tap de goma. Invertiu r\u00e0pidament la botella, de manera que l\u2019aigua impregni el receptacle i entri en contacte amb la magn\u00e8sia que, immediatament, comen\u00e7ar\u00e0 a emetre gas (di\u00f2xid de carboni, CO<sub>2<\/sub>), i introdu\u00efu-lo a dins del vas, que far\u00e0 els efectes de plataforma de llan\u00e7ament. Aquest gas s\u2019anir\u00e0 acumulant a l\u2019interior de la botella i la pressi\u00f3 interna s\u2019incrementar\u00e0 progressivament (podeu comprovar com el recipient s\u2019infla) fins a expulsar, de manera sobtada, el tap i l\u2019aigua de l\u2019interior. Pel principi d\u2019acci\u00f3 \u2013 reacci\u00f3, la botella (coet) s\u2019enlairar\u00e0 en sentit contrari. Podeu decorar el coet al vostre gust, abans del llan\u00e7ament.<\/span><\/span><\/p>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Garamond, serif;\"><i><b><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">5. El \u201cmotor\u201d del coet<\/span><\/span><\/b><\/i><\/span><\/p>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\"> La <i>\u201cSal de Fruta <\/i><i><b>ENO<\/b><\/i><i>\u201d<\/i> cont\u00e9 una mescla s\u00f2lida de bicarbonat de sodi (NaHCO<sub>3<\/sub>) i \u00e0cid tart\u00e0ric (C<sub>4<\/sub>H<sub>6<\/sub>O<sub>6<\/sub>), que quan entra en contacte amb l\u2019aigua de la botella, reacciona segons el proc\u00e9s qu\u00edmic seg\u00fcent:<\/span><\/span><\/p>\n<p class=\"western\" lang=\"ca-ES\" style=\"text-align: center;\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">2NaHCO<sub>3(s)<\/sub>+ C<sub>4<\/sub>H<sub>6<\/sub>O<sub>6(s)<\/sub> \u2192 Na<sub>2<\/sub>C<sub>4<\/sub>H<sub>4<\/sub>O<sub>6(aq.) <\/sub>+ 2H<sub>2<\/sub>O<sub>(l)<\/sub>+2CO<sub>2(g) <\/sub>\u2191<\/span><\/span><\/p>\n<p class=\"western\" lang=\"ca-ES\" style=\"text-align: left;\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\"><i><b>6. Els c\u00e0lculs i els resultats<\/b><\/i><\/span><\/span><\/p>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\"> Amb el cron\u00f2metre, mesureu el temps total de vol del coet en segons, des de que es dispara fins que impacta de nou contra terra. Anomenarem aquest temps, T. Amb aquesta dada, podem con\u00e8ixer:<\/span><\/span><\/p>\n<ul>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">La velocitat inicial (v<sub>0, <\/sub>en m\/s) amb qu\u00e8 el coet s\u2019enlaira des del vas: v<sub>0<\/sub> = 0,5\u00b7g\u00b7T, on <i>g<\/i> \u00e9s el valor del camp gravitatori terrestre a la seva superf\u00edcie, i val 9,8 m\/s<sup>2<\/sup>.<\/span><\/span><\/p>\n<\/li>\n<li>\n<p class=\"western\" lang=\"ca-ES\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">L\u2019al\u00e7ada m\u00e0xima (H, en metres) que assoleix el coet la podem trobar a partir de l\u2019expressi\u00f3:<\/span><\/span><\/p>\n<\/li>\n<\/ul>\n<p class=\"western\" lang=\"ca-ES\" style=\"text-align: center;\" align=\"justify\"><span style=\"font-family: Arial, sans-serif;\"><span style=\"font-size: small;\">H = 0,5\u00b7v<sub>0<\/sub>\u00b7T \u2013 0,125\u00b7g\u00b7T<sup>2<\/sup><\/span><\/span><\/p>\n<div class=\"ast-oembed-container \" style=\"height: 100%;\"><iframe loading=\"lazy\" title=\"Taller de coets d&#039;aigua\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/DVn7tnRzDx8?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Presentaci\u00f3 i principis f\u00edsics del coet El moviment dels coets i d\u2019altres aeronaus es basa en el conegut principi d\u2019acci\u00f3 \u2013 reacci\u00f3, segons el qual si una part d\u2019un objecte es accelerat en un sentit, l\u2019altra part de l\u2019objecte es mou espont\u00e0niament en sentit contrari, de manera que l\u2019efecte global sobre la totalitat de l\u2019objecte [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":3851,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center 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