{"id":2188,"date":"2016-05-14T22:40:57","date_gmt":"2016-05-14T22:40:57","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=2188"},"modified":"2024-09-02T14:35:19","modified_gmt":"2024-09-02T14:35:19","slug":"refracao-luminosa","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/optica\/optica-geometrica\/refracao-luminosa\/","title":{"rendered":"Refra\u00e7\u00e3o Luminosa"},"content":{"rendered":"

Refra\u00e7\u00e3o Luminosa \u2013 Conceitos e Defini\u00e7\u00f5es<\/b><\/span><\/span><\/span><\/p>\n

Refra\u00e7\u00e3o<\/b><\/span><\/span><\/span><\/p>\n

A <\/b><\/span><\/span><\/span><\/span>refra\u00e7\u00e3o da luz <\/b><\/span><\/span><\/span><\/span>\u00e9 um <\/b><\/span><\/span><\/span><\/span>fen\u00f4meno<\/b><\/span><\/span><\/span><\/span> que ocorre quando a <\/b><\/span><\/span><\/span><\/span>luz passa de um meio para outro, variando sua velocidade de propaga\u00e7\u00e3o e sofrendo desvio<\/b><\/span><\/span><\/span><\/span>, como observamos nas <\/b><\/span><\/span><\/span><\/span>figuras abaixo<\/b><\/span><\/span><\/span><\/span>.onde os <\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"\u00a0\u00a0<\/span>raios de luz ao passarem de um meio para outro<\/b><\/span><\/span><\/span><\/span> <\/b>sofrem desvios <\/b><\/span><\/span><\/span><\/span>e parecem \u201cquebrados\u201d.<\/b><\/span><\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><\/p>\n

Fen\u00f4menos que ocorrem junto com a refra\u00e7\u00e3o da luz<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O <\/b><\/span><\/span><\/span><\/span>fen\u00f4meno da refra\u00e7\u00e3o ocorre simult\u00e2neamente <\/b><\/span><\/span><\/span><\/span>com os <\/b><\/span><\/span><\/span><\/span>fen\u00f4menos da reflex\u00e3o e absor\u00e7\u00e3o <\/b><\/span><\/span><\/span><\/span><\/p>\n

mas <\/b><\/span><\/span><\/span><\/span>predomina se os dois meios forem transparentes. <\/b><\/span><\/span><\/span><\/span><\/p>\n

\u00cdndice de refra\u00e7\u00e3o<\/b><\/span><\/span><\/span><\/span><\/p>\n

Quando a <\/b><\/span><\/span><\/span>luz passa de um meio transparente para outro, <\/b><\/span><\/span><\/span>sua <\/b><\/span><\/span><\/span>velocidade aumenta ou diminui <\/b><\/span><\/span><\/span>devido as <\/b><\/span><\/span><\/span>diferen\u00e7as das estruturas at\u00f4micas das duas subst\u00e2ncias, ou de suas densidades \u00f3pticas ou \u00edndices de refra\u00e7\u00e3o.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A <\/b><\/span><\/span><\/span><\/span>maior velocidade da luz ocorre quando ela se propaga no v\u00e1cuo<\/b><\/span><\/span><\/span><\/span> <\/b>( e aproximadamente ) <\/b><\/span><\/span><\/span><\/span>no ar,<\/b><\/span><\/span><\/span><\/span> que \u00e9 uma <\/b><\/span><\/span><\/span><\/span>constante denominada de<\/b><\/span><\/span><\/span><\/span>\u00a0c<\/b><\/span><\/span><\/span><\/span> \u00a0<\/b><\/span><\/span><\/span><\/span>e cujo <\/b><\/span><\/span><\/span><\/span>valor \u00e9 c = 3.10<\/b><\/span><\/span><\/span><\/span>8 <\/b><\/span><\/span><\/span><\/sup><\/span>m\/s. <\/b><\/span><\/span><\/span><\/span><\/p>\n

Em <\/b><\/span><\/span><\/span><\/span>qualquer outro meio refringente <\/b><\/span><\/span><\/span><\/span>(que <\/b><\/span><\/span><\/span><\/span>oferece interfer\u00eancia <\/b><\/span><\/span><\/span><\/span>\u00e0 passagem da luz), que seja <\/b><\/span><\/span><\/span><\/span>homog\u00eaneo e transparente, <\/b><\/span><\/span><\/span><\/span>a <\/b><\/span><\/span><\/span><\/span>velocidade da luz (V), <\/b><\/span><\/span><\/span><\/span>\u00e9 <\/b><\/span><\/span><\/span><\/span>menor que c. <\/b><\/span><\/span><\/span><\/span><\/p>\n

O <\/b><\/span><\/span><\/span><\/span>\u00edndice de refra\u00e7\u00e3o de um meio material depende do tipo de luz monocrom\u00e1tica que nele se propaga. <\/b><\/span><\/span><\/span><\/span><\/p>\n

Quando <\/b><\/span><\/span><\/span><\/span>queremos indicar, <\/b><\/span><\/span><\/span><\/span>entre <\/b><\/span><\/span><\/span><\/span>dois meios<\/b><\/span><\/span><\/span><\/span>, qual tem <\/b><\/span><\/span><\/span><\/span>maior \u00edndice de refra\u00e7\u00e3o, <\/b><\/span><\/span><\/span><\/span>costumamos utilizar o <\/b><\/span><\/span><\/span><\/span>termo refring\u00eancia. <\/b><\/span><\/span><\/span><\/span>Ent\u00e3o, o <\/b><\/span><\/span><\/span><\/span>meio que possuir menor \u00edndice de refra\u00e7\u00e3o ser\u00e1 menos refringente.<\/b><\/span><\/span><\/span><\/span>\"\"<\/p>\n

Assim, na <\/b><\/span><\/span><\/span>tabela ao lado o diamante \u00e9 mais refringente que o vidro, que por sua vez \u00e9 mais refringente que a \u00e1gua.<\/b><\/span><\/span><\/span><\/p>\n

Significado f\u00edsico do \u00edndice de refra\u00e7\u00e3o de um dado meio<\/b><\/span><\/span><\/span><\/span><\/p>\n

O <\/b><\/span><\/span><\/span><\/span>\u00edndice de refra\u00e7\u00e3o de um meio <\/b><\/span><\/span><\/span><\/span>representa a <\/b><\/span><\/span><\/span><\/span>raz\u00e3o (compara\u00e7\u00e3o) <\/b><\/span><\/span><\/span><\/span>entre a <\/b><\/span><\/span><\/span><\/span>velocidade da luz no v\u00e1cuo e \u00a0a velocidade da luz no meio, ou seja:<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Caracter\u00edsticas importantes sobre o \u00edndice de refra\u00e7\u00e3o<\/b><\/span><\/span><\/span><\/p>\n

\"\" O <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o \u00e9 uma grandeza adimensional, <\/b><\/span><\/span><\/span><\/em>isto \u00e9, n\u00e3o <\/b><\/span><\/span><\/span><\/em>possui unidade de medida, j\u00e1 que \u00e9 a raz\u00e3o entre duas grandezas de mesma unidade (velocidades)<\/b><\/span><\/span><\/span><\/em>.<\/b><\/span><\/span><\/span><\/p>\n

\"\" O <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o do v\u00e1cuo<\/b><\/span><\/span><\/span><\/em>, por hip\u00f3tese, \u00e9 <\/b><\/span><\/span><\/span><\/em>igual a 1.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\" Qualquer <\/b><\/span><\/span><\/span><\/em>meio material refringente <\/b><\/span><\/span><\/span><\/em>(que <\/b><\/span><\/span><\/span><\/span>oferece interfer\u00eancia <\/b><\/span><\/span><\/span><\/span>\u00e0 passagem da luz),<\/b><\/span><\/span><\/span><\/span> deve ter um <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o maior do que 1.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\" O <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o de determinado meio<\/b><\/span><\/span><\/span><\/em> indica <\/b><\/span><\/span><\/span><\/em>quantas vezes a velocidade da luz no v\u00e1cuo \u00e9 maior do que naquele meio.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\" Quando <\/b><\/span><\/span><\/span><\/em>comparamos meios \u00f3pticos transparentes<\/b><\/span><\/span><\/span><\/em>, \u00e9 comum <\/b><\/span><\/span><\/span><\/em>utilizar o termo refring\u00eancia, <\/b><\/span><\/span><\/span><\/em>portanto dizemos que um <\/b><\/span><\/span><\/span><\/em>meio A \u00e9 mais refringente que o meio B, se o \u00edndice de refra\u00e7\u00e3o de A for maior que o \u00edndice de refra\u00e7\u00e3o de B.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\" O <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o absoluto <\/b><\/span><\/span><\/span><\/em>\u00e9 <\/b><\/span><\/span><\/span><\/em>inversamente proporcional \u00e0 velocidade de propaga\u00e7\u00e3o da luz no meio<\/b><\/span><\/span><\/span><\/em>, isto \u00e9, quanto <\/b><\/span><\/span><\/span><\/em>menor for a velocidade de propaga\u00e7\u00e3o da luz, maior ser\u00e1 o \u00edndice de refra\u00e7\u00e3o do meio.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\" O <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o <\/b><\/span><\/span><\/span><\/em>de um <\/b><\/span><\/span><\/span><\/em>meio material depende da cor da luz monocrom\u00e1tica que est\u00e1 se propagando nesse meio.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\u00cdndice de refra\u00e7\u00e3o relativo<\/b><\/span><\/span><\/span><\/p>\n

Definimos o<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u00edndice de refra\u00e7\u00e3o relativo<\/b><\/span><\/span><\/span><\/em>\u00a0<\/b><\/span><\/span><\/span>do meio A em rela\u00e7\u00e3o ao meio B, <\/b><\/span><\/span><\/span>n<\/b><\/span><\/span><\/span>AB<\/b><\/span><\/span><\/sub><\/span> como sendo <\/b><\/span><\/span><\/span>a raz\u00e3o <\/b><\/span><\/span><\/span>entre o<\/b><\/span><\/span><\/span> \u00edndice de refra\u00e7\u00e3o absoluto do meio A (n<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>) <\/b><\/span><\/span><\/span>e o<\/b><\/span><\/span><\/span> \u00edndice de refra\u00e7\u00e3o absoluto do meio B (n<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>), <\/b><\/span><\/span><\/span>ou<\/b><\/span><\/span><\/span> <\/b>seja,<\/b><\/span><\/span><\/span> n<\/b><\/span><\/span><\/span>AB<\/b><\/span><\/span><\/sub><\/span> = n<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>\/<\/b><\/span><\/span><\/span>n<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span> (nessa ordem).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Desvio na refra\u00e7\u00e3o<\/b><\/span><\/span><\/span><\/p>\n

O <\/b><\/span><\/span><\/span><\/span>desvio (d)<\/b><\/span><\/span><\/span><\/span> <\/b>na <\/b><\/span><\/span><\/span><\/span>refra\u00e7\u00e3o corresponde ao \u00e2ngulo entre o prolongamento do raio incidente e o raio refratado (figura da esquerda).<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

No caso da <\/b><\/span><\/span><\/span><\/span>incid\u00eancia ser normal o raio de luz n\u00e3o sofre desvio e d = 0 (figura da direita).<\/b><\/span><\/span><\/span><\/span><\/p>\n

Importante:<\/b><\/span><\/span><\/span><\/span> <\/b>Quanto <\/b><\/span><\/span><\/span><\/span>maior<\/b><\/span><\/span><\/span><\/span> for o \u00edndice de refra\u00e7\u00e3o de um meio, <\/b><\/span><\/span><\/span><\/span>menor<\/b><\/span><\/span><\/span><\/span> ser\u00e1 a velocidade da luz nele e <\/b><\/span><\/span><\/span><\/span>maior ser\u00e1 o desvio sofrido.<\/b><\/span><\/span><\/span><\/span><\/p>\n

O que voc\u00ea deve saber, informa\u00e7\u00f5es e dicas<\/b><\/span><\/span><\/span><\/p>\n

\"\" O <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o \u00e9 uma grandeza adimensional, <\/b><\/span><\/span><\/span><\/em>isto \u00e9, n\u00e3o <\/b><\/span><\/span><\/span><\/em>possui unidade de medida, j\u00e1 que \u00e9 a raz\u00e3o entre duas grandezas de mesma unidade (velocidades)<\/b><\/span><\/span><\/span><\/em>.<\/b><\/span><\/span><\/span><\/p>\n

\"\" O <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o do v\u00e1cuo<\/b><\/span><\/span><\/span><\/em>, por hip\u00f3tese, \u00e9 <\/b><\/span><\/span><\/span><\/em>igual a 1.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\" Qualquer <\/b><\/span><\/span><\/span><\/em>meio material refringente <\/b><\/span><\/span><\/span><\/em>(que <\/b><\/span><\/span><\/span><\/span>oferece interfer\u00eancia <\/b><\/span><\/span><\/span><\/span>\u00e0 passagem da luz),<\/b><\/span><\/span><\/span><\/span> deve ter um <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o maior do que 1.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\" O <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o de determinado meio<\/b><\/span><\/span><\/span><\/em> indica <\/b><\/span><\/span><\/span><\/em>quantas vezes a velocidade da luz no v\u00e1cuo \u00e9 maior do que naquele meio.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\" Quando <\/b><\/span><\/span><\/span><\/em>comparamos meios \u00f3pticos transparentes<\/b><\/span><\/span><\/span><\/em>, \u00e9 comum <\/b><\/span><\/span><\/span><\/em>utilizar o termo refring\u00eancia, <\/b><\/span><\/span><\/span><\/em>portanto dizemos que um <\/b><\/span><\/span><\/span><\/em>meio A \u00e9 mais refringente que o meio B, se o \u00edndice de refra\u00e7\u00e3o de A for maior que o \u00edndice de refra\u00e7\u00e3o de B.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\" O <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o absoluto <\/b><\/span><\/span><\/span><\/em>\u00e9 <\/b><\/span><\/span><\/span><\/em>inversamente proporcional \u00e0 velocidade de propaga\u00e7\u00e3o da luz no meio<\/b><\/span><\/span><\/span><\/em>, isto \u00e9, quanto <\/b><\/span><\/span><\/span><\/em>menor for a velocidade de propaga\u00e7\u00e3o da luz, maior ser\u00e1 o \u00edndice de refra\u00e7\u00e3o do meio.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\" O <\/b><\/span><\/span><\/span><\/em>\u00edndice de refra\u00e7\u00e3o <\/b><\/span><\/span><\/span><\/em>de um <\/b><\/span><\/span><\/span><\/em>meio material depende da cor da luz monocrom\u00e1tica que est\u00e1 se propagando nesse meio.<\/b><\/span><\/span><\/span><\/em><\/p>\n

\"\"<\/p>\n

Continuidade \u00d3ptica<\/b><\/span><\/span><\/span><\/p>\n

Consideremos <\/b><\/span><\/span><\/span>dois meios transparentes A e B e um feixe de luz dirigindo-se de A para B.<\/b><\/span><\/span><\/span><\/p>\n

Para que <\/b><\/span><\/span><\/span>haja feixe refletido \u00e9 necess\u00e1rio que n<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>\u00a0seja diferente de n<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

Quando <\/b><\/span><\/span><\/span>n<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>\u00a0= n<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>, <\/b><\/span><\/span><\/span>n\u00e3o h\u00e1 luz refletida<\/b><\/span><\/span><\/span> <\/b>e tamb\u00e9m <\/b><\/span><\/span><\/span>n\u00e3o h\u00e1 mudan\u00e7a na dire\u00e7\u00e3o da luz<\/b><\/span><\/span><\/span> ao mudar de meio; <\/b><\/span><\/span><\/span>nesse caso <\/b><\/span><\/span><\/span>dizemos que <\/b><\/span><\/span><\/span>h\u00e1 continuidade \u00f3ptica.<\/b><\/span><\/span><\/span><\/p>\n

Quando temos um <\/b><\/span><\/span><\/span>bast\u00e3o de vidro dentro de um recipiente contendo um l\u00edquido<\/b><\/span><\/span><\/span> com o <\/b><\/span><\/span><\/span>mesmo \u00edndice de refra\u00e7\u00e3o do vidro, a parte do bast\u00e3o que est\u00e1 submersa, n\u00e3o refletindo a luz, fica “invis\u00edvel\u201d<\/b><\/span><\/span><\/span><\/p>\n

Exemplo de <\/b><\/span><\/span><\/span>continuidade \u00f3ptica (vidro imerso em tetracloroetileno)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

\"\" A\u00a0<\/b><\/span><\/span><\/span><\/span>Dispers\u00e3o luminosa <\/b><\/span><\/span><\/span>no\u00a0arco-\u00edris<\/b><\/span><\/span><\/span> ocorre\u00a0<\/b><\/span><\/span><\/span>naturalmente<\/b><\/span><\/span><\/span>\u00a0e \u00e9 resultado do <\/b><\/span><\/span><\/span>espalhamento da luz em gotas de \u00e1gua em suspens\u00e3o na atmosfera. <\/b><\/span><\/span><\/span><\/p>\n

A luz sofre\u00a0refra\u00e7\u00e3o\u00a0ao entrar e sair da gota, <\/b><\/span><\/span><\/span>e\u00a0<\/b><\/span><\/span><\/span>reflex\u00e3o\u00a0dentro da gota<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

N\u00e3o h\u00e1 difra\u00e7\u00e3o envolvida, <\/b><\/span><\/span><\/span>visto que as <\/b><\/span><\/span><\/span>dimens\u00f5es envolvidas s\u00e3o muito maiores que o comprimento de onda da luz.<\/b><\/span><\/span><\/span><\/p>\n

Na figura da esquerda<\/b><\/span><\/span><\/span>, <\/b><\/span><\/span><\/span>em 1 <\/b><\/span><\/span><\/span>ocorre <\/b><\/span><\/span><\/span>refra\u00e7\u00e3o<\/b><\/span><\/span><\/span>, em <\/b><\/span><\/span><\/span>2 reflex\u00e3o, <\/b><\/span><\/span><\/span>e em <\/b><\/span><\/span><\/span>3 nova refra\u00e7\u00e3o.<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Entre 1 e 2 e entre 2 e 3, ocorre dispers\u00e3o.\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\u00a0<\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

Observe na figura, que na <\/b><\/span><\/span><\/span>dispers\u00e3o da luz<\/b><\/span><\/span><\/span> solar que provoca o arco-\u00edris, a luz retorna ao meio original e, para que isso<\/b><\/span><\/span><\/span><\/p>\n

aconte\u00e7a o Sol tem que estar atr\u00e1s do observador.\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\"\" A <\/b><\/span><\/span><\/span>dispers\u00e3o luminosa<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>ocorre <\/b><\/span><\/span><\/span>artificialmente<\/b><\/span><\/span><\/span>\u00a0quando a <\/b><\/span><\/span><\/span>luz se dispersa como no interior de um prisma (figura da esquerda) ou passa do ar para a \u00e1gua (figura da direita), <\/b><\/span><\/span><\/span>sendo <\/b><\/span><\/span><\/span>mais desviada a luz <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

monocrom\u00e1tica violeta <\/b><\/span><\/span><\/span>(menor velocidade) e <\/b><\/span><\/span><\/span>menos desviada a luz monocrom\u00e1tica vermelha <\/b><\/span><\/span><\/span>(maior velocidade). <\/b><\/span><\/span><\/span><\/p>\n

Lembre-se que <\/b><\/span><\/span><\/span>essa dispers\u00e3o ocorre com uma\u00a0infinidade\u00a0de cores <\/b><\/span><\/span><\/span>(infinidades de frequ\u00eancias) <\/b><\/span><\/span><\/span>que est\u00e3o compreendidas entre o vermelho e o violeta.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Predomin\u00e2ncia da refra\u00e7\u00e3o e da reflex\u00e3o de acordo a incid\u00eancia da luz<\/b><\/span><\/span><\/span><\/p>\n

Durante o dia, <\/b><\/span><\/span><\/span>uma pessoa <\/b><\/span><\/span><\/span>dentro de casa olha atrav\u00e9s do vidro de uma janela e enxerga o que est\u00e1 do lado de fora.<\/b><\/span><\/span><\/span>\"\"<\/p>\n

\u00c0 noite, <\/b><\/span><\/span><\/span>a pessoa <\/b><\/span><\/span><\/span>olha atrav\u00e9s da mesma janela e enxerga sua imagem refletida pelo vidro, n\u00e3o enxergando o que est\u00e1 do lado de fora. <\/b><\/span><\/span><\/span><\/p>\n

Isso ocorre porque <\/b><\/span><\/span><\/span>durante o dia, a luz que atravessa o vidro da janela, proveniente dos objetos localizados no exterior da casa, \u00e9 muito mais intensa que a luz refletida pelo vidro da janela, predominando a refra\u00e7\u00e3o (luz externa mais intensa). <\/b><\/span><\/span><\/span><\/p>\n

J\u00e1, durante <\/b><\/span><\/span><\/span>a noite a luz interna \u00e9 mais intensa que a externa, predominando a reflex\u00e3o interna..<\/b><\/span><\/span><\/span><\/p>\n

 <\/p>\n

Confira os exerc\u00edcios com resolu\u00e7\u00e3o comentada<\/span><\/a><\/h3>\n

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

Refra\u00e7\u00e3o Luminosa \u2013 Conceitos e Defini\u00e7\u00f5es Refra\u00e7\u00e3o A refra\u00e7\u00e3o da luz \u00e9 um fen\u00f4meno que ocorre quando a luz passa de um meio para outro, variando sua velocidade de propaga\u00e7\u00e3o e sofrendo desvio, como observamos nas figuras abaixo.onde os \u00a0\u00a0raios de luz ao passarem de um meio para outro sofrem desvios e parecem \u201cquebrados\u201d. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Fen\u00f4menos que ocorrem junto com<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2137,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-2188","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2188","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/comments?post=2188"}],"version-history":[{"count":2,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2188\/revisions"}],"predecessor-version":[{"id":2195,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2188\/revisions\/2195"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2137"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=2188"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}