{"id":3450,"date":"2025-09-18T08:00:10","date_gmt":"2025-09-18T06:00:10","guid":{"rendered":"http:\/\/www.zsvltava.cz\/fyzika\/?p=3450"},"modified":"2025-12-18T11:46:07","modified_gmt":"2025-12-18T10:46:07","slug":"prace","status":"publish","type":"post","link":"https:\/\/www.zsvltava.cz\/fyzika\/?p=3450","title":{"rendered":"Pr\u00e1ce jako fyzik\u00e1ln\u00ed veli\u010dina"},"content":{"rendered":"

Pr\u00e1ci ozna\u010dujeme W (anglicky: work). Jednotkou je Joule<\/a> (\u010dti: d\u017eaul). Pr\u00e1ci kon\u00e1me pr\u00e1ci, pokud p\u016fsob\u00edme silou po ur\u010dit\u00e9 dr\u00e1ze<\/strong>. Co\u017e zap\u00ed\u0161eme:<\/p>\n

W = F . s<\/strong><\/p>\n

Tento vzore\u010dek plat\u00ed, kdy\u017e s\u00edla<\/a> p\u016fsob\u00ed ve sm\u011bru pohybu.<\/p>\n

Francie, p\u00ed\u0161e se rok 1826<\/h2>\n

P\u0159edstav si Pa\u0159\u00ed\u017e za\u010d\u00e1tku 19. stolet\u00ed. Parou poh\u00e1n\u011bn\u00e9 stroje za\u010d\u00ednaj\u00ed m\u011bnit sv\u011bt, pr\u016fmyslov\u00e1 revoluce je v pln\u00e9m proudu. In\u017een\u00fd\u0159i sice dovedou konstruovat parn\u00ed stroje a vodn\u00ed kola, ale chyb\u00ed jim p\u0159esn\u00fd jazyk \u2013 fyzik\u00e1ln\u00ed jazyk \u2013 kter\u00fdm by popsali, co vlastn\u011b tyto stroje \u201ed\u011blaj\u00ed\u201c. Kdy\u017e n\u011bkdo \u0159\u00edk\u00e1, \u017ee \u201estroj ud\u011blal hodn\u011b pr\u00e1ce\u201c, je to sp\u00ed\u0161 obrazn\u00fd pojem. Ale co to pr\u00e1ce vlastn\u011b je?<\/p>\n

Gaspard-Gustave de Coriolis<\/h2>\n

\"\"<\/p>\n

Coriolis nebyl in\u017een\u00fdr v mont\u00e9rk\u00e1ch \u2013 byl to teoretik, p\u0159edn\u00e1\u0161ej\u00edc\u00ed na slavn\u00e9 pa\u0159\u00ed\u017esk\u00e9 \u00c9cole Polytechnique. Zaj\u00edmalo ho, jak mechanika plat\u00ed pro re\u00e1ln\u00e9 stroje \u2013 zejm\u00e9na pro stroje, kter\u00e9 se pohybuj\u00ed rota\u010dn\u011b. Jeho c\u00edlem bylo spojit teorii a praxi.<\/p>\n

V roce 1826 napsal \u010dl\u00e1nek s nen\u00e1padn\u00fdm n\u00e1zvem:<\/p>\n

„M\u00e9moire sur les lois du mouvement des corps“<\/em> (Pojedn\u00e1n\u00ed o z\u00e1konech pohybu t\u011bles)<\/p>\n

V tomto textu jako prvn\u00ed p\u0159esn\u011b definoval \u201epr\u00e1ci\u201c jako fyzik\u00e1ln\u00ed veli\u010dinu \u2013 mno\u017estv\u00ed energie p\u0159enesen\u00e9 silou p\u016fsob\u00edc\u00ed po ur\u010dit\u00e9 dr\u00e1ze.<\/p>\n

V t\u00e9 dob\u011b to byla radik\u00e1ln\u00ed novinka. Ostatn\u00ed fyzikov\u00e9 a in\u017een\u00fd\u0159i mu nerozum\u011bli nebo mu nev\u011b\u0159ili. P\u0159edstava, \u017ee s\u00edla p\u016fsob\u00edc\u00ed po dr\u00e1ze vytv\u00e1\u0159\u00ed \u201en\u011bco m\u011b\u0159iteln\u00e9ho\u201c \u2013 jednotku pr\u00e1ce \u2013 zn\u011bla p\u0159\u00edli\u0161 abstraktn\u011b.<\/p>\n

Coriolis to p\u0159esto dot\u00e1hl do konce. Nejen \u017ee pr\u00e1ci definoval, ale tak\u00e9 navrhl jednotku pr\u00e1ce \u2013 kilogrammetr (tedy s\u00edla jednoho kilogramu na dr\u00e1ze jednoho metru). To byl p\u0159edch\u016fdce dne\u0161n\u00edho joulu.<\/p>\n

Sv\u00e9ho uzn\u00e1n\u00ed se do\u010dkal a\u017e po smrti. Ale tak u\u017e to ve sv\u011bt\u011b v\u011bdy b\u00fdv\u00e1. Gaspard-Gustave de Coriolis zem\u0159el v Pa\u0159\u00ed\u017ei, pom\u011brn\u011b mlad\u00fd, ve v\u011bku pouh\u00fdch 52 let. P\u0159\u00ed\u010dina nen\u00ed zn\u00e1ma, jedin\u00e9 co v\u00edme, \u017ee m\u011bl Coriolis velmi k\u0159ehk\u00e9 zdrav\u00ed, nebo\u0165 v ml\u00e1d\u00ed prod\u011blal z\u00e1va\u017en\u00e9 infek\u010dn\u00ed onemocn\u011bn\u00ed.<\/p>\n

Pr\u00e1ce, kdy\u017e nep\u016fsob\u00ed s\u00edla ve sm\u011bru pohybu<\/h2>\n

W = F . s . cos(α)<\/strong><\/p>\n

cos?<\/h3>\n

Funkce cos (cosinus) je goniometrick\u00e1 funkce. T\u00fdk\u00e1 se pom\u011br\u016f stran v pravo\u00fahl\u00e9m troj\u00faheln\u00edku. Je to \u010d\u00edslo mezi 0 a 1. Snadno jej vypo\u010d\u00edt\u00e1me pomoc\u00ed kalkula\u010dky.<\/p>\n

\"\"<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Pr\u00e1ci ozna\u010dujeme W (anglicky: work). Jednotkou je Joule (\u010dti: d\u017eaul). Pr\u00e1ci kon\u00e1me pr\u00e1ci, pokud p\u016fsob\u00edme silou po ur\u010dit\u00e9 dr\u00e1ze. Co\u017e zap\u00ed\u0161eme: W = F . …. <\/p>\n","protected":false},"author":1,"featured_media":6075,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[44],"tags":[67,93],"class_list":["post-3450","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-prace-a-energie","tag-historie","tag-vzorecek"],"_links":{"self":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/3450","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=3450"}],"version-history":[{"count":10,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/3450\/revisions"}],"predecessor-version":[{"id":6247,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/3450\/revisions\/6247"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/media\/6075"}],"wp:attachment":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3450"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3450"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3450"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}