{"id":5686,"date":"2025-04-08T08:13:15","date_gmt":"2025-04-08T06:13:15","guid":{"rendered":"https:\/\/www.zsvltava.cz\/fyzika\/?p=5686"},"modified":"2025-04-10T07:26:00","modified_gmt":"2025-04-10T05:26:00","slug":"vztlakova-sila","status":"publish","type":"post","link":"https:\/\/www.zsvltava.cz\/fyzika\/?p=5686","title":{"rendered":"Vztlakov\u00e1 s\u00edla"},"content":{"rendered":"

Vztlakov\u00e1 s\u00edla je neviditeln\u00e1 s\u00edla, kter\u00e1 nadn\u00e1\u0161\u00ed t\u011blesa v kapalin\u011b nebo v plynu. D\u00edky n\u00ed plave lo\u010f na vod\u011b a bal\u00f3nek stoup\u00e1 vzh\u016fru ve vzduchu. Vztlakov\u00e1 s\u00edla p\u016fsob\u00ed ve v\u0161ech tekutin\u00e1ch. Vztlakov\u00e1 s\u00edla je to, co c\u00edt\u00ed\u0161, \u017ee t\u011b vyn\u00e1\u0161\u00ed zp\u00e1tky na hladinu, kdy\u017e sko\u010d\u00ed\u0161 do vody.<\/strong> <\/p>\n

Jak vznik\u00e1 vztlakov\u00e1 s\u00edla?<\/h2>\n

Kdy\u017e pono\u0159\u00edme t\u011bleso do kapaliny (nap\u0159\u00edklad do vody), kapalina za\u010dne na t\u011bleso p\u016fsobit silou sm\u011brem vzh\u016fru. Tato s\u00edla se naz\u00fdv\u00e1 vztlakov\u00e1 s\u00edla. Vznik\u00e1 proto, \u017ee tlak vody z\u00e1le\u017e\u00ed na hloubce. Ve v\u011bt\u0161\u00edch hloubk\u00e1ch nam\u011b\u0159\u00edme vy\u0161\u0161\u00ed tlak.<\/p>\n

P\u0159\u00edklady fungov\u00e1n\u00ed vztlakov\u00e9 s\u00edly<\/h2>\n

Obrovsk\u00e9 lod\u011b z ocele plavou na vod\u011b pr\u00e1v\u011b d\u00edky vztlakov\u00e9 s\u00edle!<\/h3>\n

A\u010dkoliv je ocel t\u011b\u017e\u0161\u00ed ne\u017e voda, lo\u010f m\u00e1 uvnit\u0159 spoustu vzduchu a jej\u00ed celkov\u00e1 hustota je ni\u017e\u0161\u00ed ne\u017e hustota vody. D\u00edky tomu lo\u010f vytla\u010d\u00ed dost vody, aby vztlakov\u00e1 s\u00edla unesla jej\u00ed v\u00e1hu \u2013 a tak plave!<\/p>\n

Horkovzdu\u0161n\u00fd bal\u00f3n l\u00e9t\u00e1 d\u00edky vztlaku ve vzduchu<\/h3>\n

Tepl\u00fd vzduch uvnit\u0159 balonu je leh\u010d\u00ed ne\u017e studen\u00fd vzduch kolem. Bal\u00f3n tedy \u201evytla\u010d\u00ed\u201c t\u011b\u017e\u0161\u00ed vzduch, a vztlakov\u00e1 s\u00edla ho nadn\u00e1\u0161\u00ed vzh\u016fru \u2013 podobn\u011b jako lo\u010f ve vod\u011b!<\/p>\n

Tu\u010d\u0148\u00e1ci a tuleni vyu\u017e\u00edvaj\u00ed vztlak p\u0159i plav\u00e1n\u00ed<\/h3>\n

Kdy\u017e cht\u011bj\u00ed stoupat nebo klesat ve vod\u011b, m\u011bn\u00ed mno\u017estv\u00ed vzduchu ve sv\u00fdch t\u011blech (nap\u0159\u00edklad v plic\u00edch). T\u00edm si upravuj\u00ed vztlak.<\/p>\n

Ryby maj\u00ed plynov\u00fd m\u011bch\u00fd\u0159<\/h3>\n

Pomoc\u00ed n\u011bj m\u011bn\u00ed svou hustotu \u2013 kdy\u017e ho napln\u00ed vzduchem, stoupaj\u00ed, kdy\u017e ho vypr\u00e1zdn\u00ed, klesaj\u00ed. Je to jejich \u201evztlakov\u00e1 v\u00fdbava\u201c!<\/p>\n

Led plave na vod\u011b, proto\u017ee je leh\u010d\u00ed ne\u017e voda<\/h3>\n

To je vz\u00e1cn\u00fd p\u0159\u00edpad \u2013 v\u011bt\u0161ina l\u00e1tek je v pevn\u00e9m stavu t\u011b\u017e\u0161\u00ed ne\u017e v kapaln\u00e9m, ale voda je v\u00fdjimka. D\u00edky tomu mohou \u017e\u00edt pod ledem v zim\u011b ryby \u2013 proto\u017ee led z\u016fst\u00e1v\u00e1 na hladin\u011b.<\/p>\n

Archim\u00e9d\u00e9s objevil vztlak ve van\u011b<\/h3>\n

Kdy\u017e si sedl do vany, voda p\u0159etekla \u2013 a on pochopil, \u017ee t\u011bleso vytla\u010d\u00ed tolik vody, kolik samo zabere m\u00edsta. Pr\u00fd tehdy vyk\u0159ikl \u201eHeur\u00e9ka!\u201c a b\u011b\u017eel nah\u00fd po m\u011bst\u011b. Co\u017e v t\u00e9 dob\u011b bylo ale naprosto norm\u00e1ln\u00ed. Oble\u010den\u00ed se nosilo hlavn\u011b jako projev bohatstv\u00ed a majetku a nebo kv\u016fli pr\u00e1ci.<\/p>\n

– Archim\u00e9d\u016fv z\u00e1kon<\/a>
\n– Simul\u00e1tor<\/a>
\n– Kilo pe\u0159\u00ed nebo kilo \u017eeleza? (Rozhlasov\u00e1 verze)<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Vztlakov\u00e1 s\u00edla je neviditeln\u00e1 s\u00edla, kter\u00e1 nadn\u00e1\u0161\u00ed t\u011blesa v kapalin\u011b nebo v plynu. D\u00edky n\u00ed plave lo\u010f na vod\u011b a bal\u00f3nek stoup\u00e1 vzh\u016fru ve vzduchu. …. <\/p>\n","protected":false},"author":1,"featured_media":5697,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[90,35],"tags":[],"class_list":["post-5686","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-kapaliny","category-sila"],"_links":{"self":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/5686","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5686"}],"version-history":[{"count":0,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/5686\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/media\/5697"}],"wp:attachment":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5686"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5686"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5686"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}