{"id":16904,"date":"2024-09-21T15:32:08","date_gmt":"2024-09-21T18:32:08","guid":{"rendered":"https:\/\/xequematenem.com.br\/blog\/?p=16904"},"modified":"2024-09-21T15:32:11","modified_gmt":"2024-09-21T18:32:11","slug":"questao-127-enem-2017","status":"publish","type":"post","link":"https:\/\/xequematenem.com.br\/blog\/questao-127-enem-2017\/","title":{"rendered":"Quest\u00e3o 127 -ENEM 2017"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">No manual fornecido pelo fabricante de uma ducha el\u00e9trica de 220 V \u00e9 apresentado um gr\u00e1fico com a varia\u00e7\u00e3o da temperatura da \u00e1gua em fun\u00e7\u00e3o da vaz\u00e3o para tr\u00eas condi\u00e7\u00f5es (morno, quente e superquente). Na condi\u00e7\u00e3o superquente, a pot\u00eancia dissipada \u00e9 de 6 500 W. Considere o calor espec\u00edfico da \u00e1gua igual a 4 200 J\/(kg \u00b0C) e densidade da \u00e1gua igual a 1 kg\/L.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img fetchpriority=\"high\" decoding=\"async\" width=\"344\" height=\"188\" src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-619.png\" alt=\"\" class=\"wp-image-16905\" title=\"\" srcset=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-619.png 344w, https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-619-300x164.png 300w\" sizes=\"(max-width: 344px) 100vw, 344px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Com base nas informa\u00e7\u00f5es dadas, a pot\u00eancia na condi\u00e7\u00e3o morno corresponde a que fra\u00e7\u00e3o da pot\u00eancia na condi\u00e7\u00e3o superquente?&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A 1\/3<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">B 1\/5&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C 3\/5&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">D 3\/8&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">E 5\/8<\/p>\n\n\n\n<p class=\"has-text-align-center has-large-font-size wp-block-paragraph\"><strong>Solu\u00e7\u00e3o<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A dificuldade neste problema est\u00e1 em evidenciar a vaz\u00e3o da \u00e1gua (volume por tempo). Para isso, vamos partir da express\u00e3o da pot\u00eancia \ud835\udc43 e assumir que a energia el\u00e9trica \ud835\udc38 \u00e9 totalmente transferida para a \u00e1gua, variando sua energia interna \ud835\udc38<sub>i<\/sub> num intervalo de tempo \u0394t.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"165\" height=\"52\" data-src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-620.png\" alt=\"\" class=\"wp-image-16906 lazyload\" title=\"\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 165px; --smush-placeholder-aspect-ratio: 165\/52;\"><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Da Primeira Lei da Termodin\u00e2mica, uma vez que n\u00e3o houve realiza\u00e7\u00e3o de trabalho, a varia\u00e7\u00e3o da energia interna da \u00e1gua \u00e9 equivalente \u00e0 quantidade de calor<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"123\" height=\"41\" data-src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-621.png\" alt=\"\" class=\"wp-image-16907 lazyload\" title=\"\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 123px; --smush-placeholder-aspect-ratio: 123\/41;\"><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Ent\u00e3o, onde \ud835\udc5a \u00e9 a massa, \ud835\udc50 \u00e9 o calor espec\u00edfico e \u0394T \u00e9 a varia\u00e7\u00e3o de temperatura.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ainda, a massa da \u00e1gua pode ser reescrita como sendo o produto de seu volume \ud835\udc49 por sua densidade \ud835\udc51, ent\u00e3o:&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"344\" height=\"127\" data-src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-622.png\" alt=\"\" class=\"wp-image-16908 lazyload\" title=\"\" data-srcset=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-622.png 344w, https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-622-300x111.png 300w\" data-sizes=\"(max-width: 344px) 100vw, 344px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 344px; --smush-placeholder-aspect-ratio: 344\/127;\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">A vaz\u00e3o aparece aqui na divis\u00e3o do volume pelo intervalo tempo, e a representaremos por \ud835\udc63. Com isso, a pot\u00eancia fica finalmente expressa na seguinte forma:&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"187\" height=\"56\" data-src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-623.png\" alt=\"\" class=\"wp-image-16909 lazyload\" title=\"\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 187px; --smush-placeholder-aspect-ratio: 187\/56;\"><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Agora, podemos escrever as express\u00f5es para as pot\u00eancias na condi\u00e7\u00e3o 1 (morno) e na condi\u00e7\u00e3o 3 (superquente), isto \u00e9,\u00a0<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"232\" height=\"37\" data-src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-626.png\" alt=\"\" class=\"wp-image-16912 lazyload\" title=\"\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 232px; --smush-placeholder-aspect-ratio: 232\/37;\"><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Donde, dividindo a equa\u00e7\u00f5es, chegamos \u00e0 seguinte rela\u00e7\u00e3o:&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"244\" height=\"73\" data-src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-625.png\" alt=\"\" class=\"wp-image-16911 lazyload\" title=\"\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 244px; --smush-placeholder-aspect-ratio: 244\/73;\"><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Com base no gr\u00e1fico do enunciado, vamos, por exemplo, escolher a vaz\u00e3o de 3 L\/min e substituir a eleva\u00e7\u00e3o de temperatura nas condi\u00e7\u00f5es 1 e 3:&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"161\" height=\"64\" data-src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-627.png\" alt=\"\" class=\"wp-image-16913 lazyload\" title=\"\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 161px; --smush-placeholder-aspect-ratio: 161\/64;\"><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">ou seja,&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"127\" height=\"61\" data-src=\"https:\/\/xequematenem.com.br\/blog\/wp-content\/uploads\/2024\/09\/image-628.png\" alt=\"\" class=\"wp-image-16914 lazyload\" title=\"\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 127px; --smush-placeholder-aspect-ratio: 127\/61;\"><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Alternativa D<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>No manual fornecido pelo fabricante de uma ducha el\u00e9trica de 220 V \u00e9 apresentado um gr\u00e1fico com a varia\u00e7\u00e3o da temperatura da \u00e1gua em fun\u00e7\u00e3o da vaz\u00e3o para tr\u00eas condi\u00e7\u00f5es (morno, quente e superquente). Na condi\u00e7\u00e3o superquente, a pot\u00eancia dissipada \u00e9 de 6 500 W. Considere o calor espec\u00edfico da \u00e1gua igual a 4 200 [&hellip;]<\/p>\n","protected":false},"author":11,"featured_media":16905,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17,22],"tags":[],"area-do-conhecimento":[116,121],"assunto":[],"class_list":["post-16904","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-questoes-do-enem","category-22","area-do-conhecimento-ciencias-da-natureza-e-suas-tecnologias","area-do-conhecimento-fisica"],"_links":{"self":[{"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/posts\/16904","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/comments?post=16904"}],"version-history":[{"count":1,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/posts\/16904\/revisions"}],"predecessor-version":[{"id":16915,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/posts\/16904\/revisions\/16915"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/media\/16905"}],"wp:attachment":[{"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/media?parent=16904"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/categories?post=16904"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/tags?post=16904"},{"taxonomy":"area-do-conhecimento","embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/area-do-conhecimento?post=16904"},{"taxonomy":"assunto","embeddable":true,"href":"https:\/\/xequematenem.com.br\/blog\/wp-json\/wp\/v2\/assunto?post=16904"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}