{"id":3278,"date":"2017-09-30T23:56:48","date_gmt":"2017-09-30T23:56:48","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=3278"},"modified":"2024-06-29T23:51:59","modified_gmt":"2024-06-29T23:51:59","slug":"hidrostatica-2013-2014","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/vestibulares-recentes\/mecanica\/hidrostatica-2013-2014\/","title":{"rendered":"Hidrost\u00e1tica \u2013 2013 – 2014"},"content":{"rendered":"

HIDROST\u00c1TICA \u2013 2013 – 2014<\/b><\/span><\/span><\/span><\/p>\n

01-<\/b><\/span><\/span><\/span>(FUVEST-SP-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um bloco de madeira\u00a0<\/b><\/span><\/span>imperme\u00e1vel,<\/b><\/span><\/span><\/span>\u00a0de massa\u00a0<\/b><\/span><\/span>M<\/b><\/span><\/span><\/span>\u00a0e dimens\u00f5es 2x3x3cm<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>, \u00e9 inserido muito lentamente na<\/b><\/span><\/span> <\/b>\u00e1gua de um balde, at\u00e9 a condi\u00e7\u00e3o de\u00a0<\/b><\/span><\/span>equil\u00edbrio<\/b><\/span><\/span><\/span>, com\u00a0<\/b><\/span><\/span>metade de seu volume submersa<\/b><\/span><\/span><\/span>. A\u00a0<\/b><\/span><\/span>\u00e1gua\u00a0<\/b><\/span><\/span><\/span>que vaza do balde \u00e9 coletada e num copo e\u00a0<\/b><\/span><\/span>tem massa m.\u00a0<\/b><\/span><\/span><\/span>A figura ilustra as situa\u00e7\u00f5es inicial e final; em\u00a0<\/b><\/span><\/span>ambos os casos, o balde encontra-se cheio de \u00e1gua at\u00e9 sua capacidade m\u00e1xima.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A\u00a0<\/b><\/span><\/span>rela\u00e7\u00e3o\u00a0<\/b><\/span><\/span><\/span>entre as massas\u00a0<\/b><\/span><\/span>m e M\u00a0<\/b><\/span><\/span><\/span>\u00e9 tal que<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

02-(MACKENZIE-SP-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Certa piscina cont\u00e9m\u00a0<\/b><\/span><\/span>\u00e1gua<\/b><\/span><\/span><\/span>, de\u00a0<\/b><\/span><\/span>\u00edndice de refra\u00e7\u00e3o absoluto igual a 4\/3<\/b><\/span><\/span><\/span>, e sua\u00a0<\/b><\/span><\/span>base se encontra 3,00 m <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

abaixo da superf\u00edcie\u00a0<\/b><\/span><\/span><\/span>livre. Quando uma pessoa, na beira da piscina, olha perpendicularmente para seu fundo<\/b><\/span><\/span> <\/b>(base), ter\u00e1 a impress\u00e3o de v\u00ea-lo\u00a0 <\/b><\/span><\/span>Dado: \u00cdndice de refra\u00e7\u00e3o absoluto do ar n = 1<\/b><\/span><\/span><\/span><\/p>\n

a) 2,25 m mais pr\u00f3ximo, em rela\u00e7\u00e3o \u00e0 profundidade real.<\/b><\/span><\/span><\/p>\n

b) 1,33 m mais pr\u00f3ximo, em rela\u00e7\u00e3o \u00e0 profundidade real.<\/b><\/span><\/span><\/p>\n

c) 0,75 m mais pr\u00f3ximo, em rela\u00e7\u00e3o \u00e0 profundidade real.<\/b><\/span><\/span><\/p>\n

d) 1,33 m mais distante, em rela\u00e7\u00e3o \u00e0 profundidade real.<\/b><\/span><\/span><\/p>\n

e) 0,75 m mais distante, em rela\u00e7\u00e3o \u00e0 profundidade real.<\/b><\/span><\/span><\/p>\n

03-(UNESP-SP-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um\u00a0<\/b><\/span><\/span>reservat\u00f3rio<\/b><\/span><\/span><\/span>\u00a0tem a forma de um\u00a0<\/b><\/span><\/span>paralelep\u00edpedo reto-ret\u00e2ngulo com dimens\u00f5es 2 m, 3 m e 4 m<\/b><\/span><\/span><\/span>. A\u00a0<\/b><\/span><\/span>figura 1\u00a0<\/b><\/span><\/span><\/span>o representa apoiado sobre uma superf\u00edcie plana horizontal, com\u00a0<\/b><\/span><\/span><\/span>determinado volume de \u00e1gua dentro dele, at\u00e9 a altura de 2 m.\u00a0<\/b><\/span><\/span><\/span>Nessa situa\u00e7\u00e3o, a press\u00e3o hidrost\u00e1tica<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>exercida pela \u00e1gua no\u00a0<\/b><\/span><\/span><\/span>fundo do reservat\u00f3rio \u00e9\u00a0<\/b><\/span><\/span><\/span>P<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A\u00a0<\/b><\/span><\/span>figura 2\u00a0<\/b><\/span><\/span><\/span>representa o\u00a0<\/b><\/span><\/span>mesmo reservat\u00f3rio apoiado de um modo diferente\u00a0<\/b><\/span><\/span><\/span>sobre a mesma superf\u00edcie horizontal e com a\u00a0<\/b><\/span><\/span>mesma quantidade de \u00e1gua dentro dele.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Considerando o\u00a0<\/b><\/span><\/span>sistema\u00a0<\/b><\/span><\/span><\/span>em equil\u00edbrio\u00a0<\/b><\/span><\/span><\/span>nas duas situa\u00e7\u00f5es e sendo\u00a0<\/b><\/span><\/span><\/span>P<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0<\/b><\/span><\/span><\/span>a\u00a0<\/b><\/span><\/span><\/span>press\u00e3o hidrost\u00e1tica\u00a0<\/b><\/span><\/span><\/span>exercida pela \u00e1gua no fundo do reservat\u00f3rio na\u00a0<\/b><\/span><\/span><\/span>segunda situa\u00e7\u00e3o<\/b><\/span><\/span><\/span>, \u00e9 correto afirmar que<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

04-(UNICAMP-SP-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Uma boia de sinaliza\u00e7\u00e3o mar\u00edtima muito simples pode ser constru\u00edda unindo-se dois cilindros de mesmas dimens\u00f5es e de densidades diferentes, sendo um de densidade menor e outro de densidade maior que a da \u00e1gua, tal como esquematizado na figura abaixo. Submergindo-se totalmente esta boia de sinaliza\u00e7\u00e3o na \u00e1gua, quais ser\u00e3o os pontos efetivos mais prov\u00e1veis de aplica\u00e7\u00e3o das for\u00e7as Peso e Empuxo?<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

a) Peso em B e Empuxo em B. <\/b><\/span><\/span><\/p>\n

b) Peso em C e Empuxo em A.<\/b><\/span><\/span><\/p>\n

c) Peso em C e Empuxo em B. <\/b><\/span><\/span><\/p>\n

d) Peso em B e Empuxo em C<\/b><\/span><\/span><\/p>\n

05-(PUC-MG-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Uma\u00a0<\/b><\/span><\/span>bola pl\u00e1stica cheia de ar\u00a0<\/b><\/span><\/span><\/span>est\u00e1\u00a0<\/b><\/span><\/span>presa no fundo de uma piscina<\/b><\/span><\/span><\/span>. Essa bola se\u00a0<\/b><\/span><\/span>solta e sobe at\u00e9 \u00e0<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

superf\u00edcie<\/b><\/span><\/span><\/span>. A bola se\u00a0<\/b><\/span><\/span>desloca em dire\u00e7\u00e3o \u00e0 superf\u00edcie, porque:<\/b><\/span><\/span><\/span><\/p>\n

a) a \u00e1gua da piscina faz uma for\u00e7a sobre a bola denominada empuxo.<\/b><\/span><\/span><\/p>\n

b) o empuxo da \u00e1gua \u00e9 maior que o peso da bola, enquanto a mesma estiver submersa.<\/b><\/span><\/span><\/p>\n

c) enquanto a bola estiver flutuando na superf\u00edcie da \u00e1gua, seu peso \u00e9 maior que o empuxo.<\/b><\/span><\/span><\/p>\n

d) a densidade da bola e a da \u00e1gua s\u00e3o iguais<\/b><\/span><\/span><\/p>\n

06-(PUC-PR-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

07-(PUC-RJ-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um\u00a0<\/b><\/span><\/span>objeto<\/b><\/span><\/span><\/span>\u00a0feito de um material cuja\u00a0<\/b><\/span><\/span>massa espec\u00edfica \u00e9 de\u00a0<\/b><\/span><\/span><\/span>600 kg\/m<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>flutua com\u00a0<\/b><\/span><\/span><\/span>3\/4 de seu volume<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

submerso<\/b><\/span><\/span><\/span>\u00a0em um\u00a0<\/b><\/span><\/span>l\u00edquido cuja a massa espec\u00edfica \u00e9 desconhecida<\/b><\/span><\/span><\/span>. Calcule a\u00a0<\/b><\/span><\/span>massa espec\u00edfica\u00a0<\/b><\/span><\/span><\/span>deste l\u00edquido em\u00a0<\/b><\/span><\/span>g\/cm<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sup><\/span>.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

08-(UCPel-RS-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um objeto maci\u00e7o\u00a0<\/b><\/span><\/span>flutua com 1\/3 de seu volume acima da superf\u00edcie de certo l\u00edquido.<\/b><\/span><\/span><\/span>\u00a0Assinale a<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

alternativa que cont\u00e9m a express\u00e3o que relaciona a\u00a0<\/b><\/span><\/span>massa espec\u00edfica \u03c1<\/b><\/span><\/span><\/span>o<\/b><\/span><\/span><\/sub><\/span>\u00a0desse objeto em fun\u00e7\u00e3o da<\/b><\/span><\/span><\/p>\n

massa espec\u00edfica \u03c1 do l\u00edquido<\/b><\/span><\/span><\/span>, e que, tamb\u00e9m, apresenta a considera\u00e7\u00e3o inicial que permite<\/b><\/span><\/span><\/p>\n

chegarmos \u00e0 express\u00e3o correta.<\/b><\/span><\/span><\/p>\n

(A)<\/b><\/span><\/span><\/span>\u00a0\u03c1<\/b><\/span><\/span>o<\/b><\/span><\/span><\/sub>\u00a0= 3\u03c1\/2 , a for\u00e7a de empuxo equivale a 1\/3 da for\u00e7a peso.<\/b><\/span><\/span><\/p>\n

(B)<\/b><\/span><\/span><\/span>\u00a0\u03c1<\/b><\/span><\/span>o<\/b><\/span><\/span><\/sub>\u00a0=<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u03c1\/3 , a for\u00e7a de empuxo deve ser igual a 2\/3 da for\u00e7a peso.<\/b><\/span><\/span><\/p>\n

(C)<\/b><\/span><\/span><\/span>\u00a0\u03c1<\/b><\/span><\/span>o<\/b><\/span><\/span><\/sub>\u00a0= (2\/3)\u03c1 , a for\u00e7a de empuxo deve ser igual a massa do objeto multiplicada pela acelera\u00e7\u00e3o<\/b><\/span><\/span><\/p>\n

da gravidade local.<\/b><\/span><\/span><\/p>\n

(D)<\/b><\/span><\/span><\/span>\u00a0\u03c1<\/b><\/span><\/span>o<\/b><\/span><\/span><\/sub>\u00a0= \u03c1 , a for\u00e7a de empuxo \u00e9 igual \u00e0 for\u00e7a peso.<\/b><\/span><\/span><\/p>\n

(E)<\/b><\/span><\/span><\/span>\u00a0N\u00e3o \u00e9 poss\u00edvel encontrar a express\u00e3o, pois n\u00e3o \u00e9 conhecido o volume do objeto, nem sua<\/b><\/span><\/span><\/p>\n

massa.<\/b><\/span><\/span><\/p>\n

09-(UDESC-SC-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Considere as proposi\u00e7\u00f5es relacionadas aos fluidos hidrost\u00e1ticos.<\/b><\/span><\/span><\/p>\n

I.\u00a0<\/b><\/span><\/span><\/span>A press\u00e3o diminui com a altitude acima do n\u00edvel do mar e aumenta com a profundidade abaixo da interface ar-\u00e1gua.<\/b><\/span><\/span><\/p>\n

II.\u00a0<\/b><\/span><\/span><\/span>O elevador hidr\u00e1ulico \u00e9 baseado no Princ\u00edpio de Pascal.<\/b><\/span><\/span><\/p>\n

III. Sabendo-se que a densidade do gelo, do \u00f3leo e da \u00e1gua s\u00e3o iguais a 0,92 g\/cm<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>; 0,80 g\/cm<\/b><\/span><\/span>3\u00a0<\/b><\/span><\/span><\/sup>e 1,0 g\/<\/b><\/span><\/span><\/p>\n

cm<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>, respectivamente, pode-se afirmar que o gelo afunda no \u00f3leo e flutua na \u00e1gua.<\/b><\/span><\/span><\/p>\n

IV.\u00a0<\/b><\/span><\/span><\/span>O peso aparente de um corpo completamente imerso \u00e9 menor que o peso real, devido \u00e0 a\u00e7\u00e3o da for\u00e7a de empuxo, exercida pelo l\u00edquido sobre o corpo, de cima para baixo.<\/b><\/span><\/span><\/p>\n

Assinale a alternativa correta.<\/b><\/span><\/span><\/p>\n

A. ( ) Somente as afirmativas I, II e III s\u00e3o verdadeiras.<\/b><\/span><\/span><\/p>\n

B. ( ) Somente as afirmativas II e IV s\u00e3o verdadeiras.<\/b><\/span><\/span><\/p>\n

C. ( ) Somente as afirmativas I e II s\u00e3o verdadeiras.<\/b><\/span><\/span><\/p>\n

D. ( ) Somente as afirmativas I, III e IV s\u00e3o verdadeiras.<\/b><\/span><\/span><\/p>\n

E. ( ) Todas as afirmativas s\u00e3o verdadeiras.<\/b><\/span><\/span><\/p>\n

10-(UECE-CE-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Tr\u00eas s\u00f3lidos, um cubo, um cilindro e uma esfera,\u00a0<\/b><\/span><\/span>t\u00eam massas iguais\u00a0<\/b><\/span><\/span><\/span>e distribu\u00eddas<\/b><\/span><\/span><\/p>\n

homogeneamente ao longo de seus volumes. Os s\u00f3lidos flutuam parcialmente submersos em um<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

mesmo l\u00edquido<\/b><\/span><\/span><\/span>. A\u00a0<\/b><\/span><\/span>rela\u00e7\u00e3o entre os volumes submersos\u00a0<\/b><\/span><\/span><\/span>de cada objeto \u00e9<\/b><\/span><\/span><\/p>\n

A) \u0394<\/b><\/span><\/span>cub<\/b><\/span><\/span><\/sub>\u00a0> \u0394<\/b><\/span><\/span>cil<\/b><\/span><\/span><\/sub>\u00a0> \u0394<\/b><\/span><\/span>esf<\/b><\/span><\/span><\/sub>\u00a0.<\/b><\/span><\/span><\/p>\n

B) \u0394<\/b><\/span><\/span>cub<\/b><\/span><\/span><\/sub>\u00a0= \u0394<\/b><\/span><\/span>cil<\/b><\/span><\/span><\/sub>\u00a0> \u0394<\/b><\/span><\/span>esf<\/b><\/span><\/span><\/sub>\u00a0. <\/b><\/span><\/span><\/p>\n

C) \u0394<\/b><\/span><\/span>cub<\/b><\/span><\/span><\/sub>\u00a0> \u0394<\/b><\/span><\/span>cil<\/b><\/span><\/span><\/sub>\u00a0= \u0394<\/b><\/span><\/span>esf<\/b><\/span><\/span><\/sub>\u00a0.<\/b><\/span><\/span><\/p>\n

D) \u0394<\/b><\/span><\/span>cub<\/b><\/span><\/span><\/sub>\u00a0= \u0394<\/b><\/span><\/span>cil<\/b><\/span><\/span><\/sub>\u00a0= \u0394<\/b><\/span><\/span>esf<\/b><\/span><\/span><\/sub>\u00a0.<\/b><\/span><\/span><\/p>\n

11-(UECE-CE-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Considere\u00a0<\/b><\/span><\/span>um cubo imerso em \u00e1gua<\/b><\/span><\/span><\/span>, conforme a figura a seguir.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

No ponto destacado de uma das faces desse cubo, h\u00e1 uma for\u00e7a devido \u00e0 press\u00e3o hidrost\u00e1tica exercida pela \u00e1gua. Assinale o vetor que melhor representa essa for\u00e7a.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

12-(UFJF-MG-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A figura mostra um tubo em forma de U, aberto nas extremidades, contendo \u00e1gua e merc\u00fario em equil\u00edbrio. Sendo h<\/b><\/span><\/span>1<\/b><\/span><\/span><\/sub>\u00a0a<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

diferen\u00e7a de alturas dos n\u00edveis de \u00e1gua nos dois ramos, x a profundidade da coluna de \u00e1gua no ramo da direita, h<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sub>\u00a0diferen\u00e7a de alturas entre os n\u00edveis de merc\u00fario nos dois ramos do tubo e sabendo-se que a press\u00e3o atmosf\u00e9rica \u00e9 p<\/b><\/span><\/span>atm<\/b><\/span><\/span><\/sub>, calcule:<\/b><\/span><\/span><\/p>\n

a) A press\u00e3o na interface \u00e1gua-merc\u00fario no ramo esquerdo do tubo.<\/b><\/span><\/span><\/p>\n

b) A altura h<\/b><\/span><\/span>1<\/b><\/span><\/span><\/sub>\u00a0em fun\u00e7\u00e3o da altura h<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sub>, da densidade da \u00e1gua (\u03c1<\/b><\/span><\/span>a<\/b><\/span><\/span><\/sub>) e da densidade do merc\u00fario (\u03c1<\/b><\/span><\/span>m<\/b><\/span><\/span><\/sub>).<\/b><\/span><\/span><\/p>\n

13-(UFPA-PA-014) <\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Uma\u00a0<\/b><\/span><\/span>crian\u00e7a brinca com um balde de \u00e1gua, um barquinho e uma \u00e2ncora de metal<\/b><\/span><\/span><\/span>. Na\u00a0<\/b><\/span><\/span>situa\u00e7\u00e3o \u201cA\u201d,<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

a\u00a0<\/b><\/span><\/span>crian\u00e7a coloca o barquinho flutuando na \u00e1gua<\/b><\/span><\/span><\/span>. Na\u00a0<\/b><\/span><\/span>situa\u00e7\u00e3o \u201cB\u201d,\u00a0<\/b><\/span><\/span><\/span>coloca o\u00a0<\/b><\/span><\/span>barquinho flutuando com a \u00e2ncora dentro do barquinho<\/b><\/span><\/span><\/span>. Na\u00a0<\/b><\/span><\/span>situa\u00e7\u00e3o \u201cC<\/b><\/span><\/span><\/span>\u201d,\u00a0<\/b><\/span><\/span>joga a \u00e2ncora no fundo do balde e o barquinho flutuando na superf\u00edcie da \u00e1gua<\/b><\/span><\/span><\/span>. Denotemos por\u00a0<\/b><\/span><\/span>N<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>, N<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>\u00a0e N<\/b><\/span><\/span><\/span>C<\/b><\/span><\/span><\/sub><\/span>,\u00a0<\/b><\/span><\/span><\/span>as\u00a0<\/b><\/span><\/span>alturas da superf\u00edcie da \u00e1gua do balde\u00a0<\/b><\/span><\/span><\/span>nas situa\u00e7\u00f5es\u00a0<\/b><\/span><\/span>\u201cA\u201d, \u201cB\u201d e \u201cC\u201d respectivamente<\/b><\/span><\/span><\/span>. Use a\u00a0<\/b><\/span><\/span>lei de Arquimedes para determinar qual das seguintes alternativas \u00e9 a correta.<\/b><\/span><\/span><\/span><\/p>\n

(A) N<\/b><\/span><\/span>A\u00a0<\/b><\/span><\/span><\/sub>> N<\/b><\/span><\/span>B<\/b><\/span><\/span><\/sub>\u00a0> N<\/b><\/span><\/span>C<\/b><\/span><\/span><\/sub>\u00a0<\/b><\/span><\/span><\/p>\n

(B) N<\/b><\/span><\/span>C\u00a0<\/b><\/span><\/span><\/sub>> N<\/b><\/span><\/span>B<\/b><\/span><\/span><\/sub>\u00a0> N<\/b><\/span><\/span>A<\/b><\/span><\/span><\/sub>\u00a0<\/b><\/span><\/span><\/p>\n

(C) N<\/b><\/span><\/span>B\u00a0<\/b><\/span><\/span><\/sub>> N<\/b><\/span><\/span>C<\/b><\/span><\/span><\/sub>\u00a0> N<\/b><\/span><\/span>A<\/b><\/span><\/span><\/sub>\u00a0<\/b><\/span><\/span><\/p>\n

(D) N<\/b><\/span><\/span>A\u00a0<\/b><\/span><\/span><\/sub>> N<\/b><\/span><\/span>C<\/b><\/span><\/span><\/sub>\u00a0> N<\/b><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/p>\n

(E) N<\/b><\/span><\/span>C\u00a0<\/b><\/span><\/span><\/sub>> N<\/b><\/span><\/span>B<\/b><\/span><\/span><\/sub>\u00a0> N<\/b><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/p>\n

14-(UFPR-PR-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Com o objetivo de encontrar grande quantidade de\u00a0<\/b><\/span><\/span>seres vivos nas profundezas do mar<\/b><\/span><\/span><\/span>, pesquisadores utilizando um submarino chegaram at\u00e9 a\u00a0<\/b><\/span><\/span>profundidade de 3.600 m<\/b><\/span><\/span><\/span>\u00a0no Plat\u00f4 de S\u00e3o<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

Paulo. A\u00a0<\/b><\/span><\/span>press\u00e3o interna\u00a0<\/b><\/span><\/span><\/span>no submarino foi mantida\u00a0<\/b><\/span><\/span>igual \u00e0 press\u00e3o atmosf\u00e9rica ao n\u00edvel do mar.\u00a0<\/b><\/span><\/span><\/span>Considere que a\u00a0<\/b><\/span><\/span>press\u00e3o atmosf\u00e9rica ao n\u00edvel do mar \u00e9 de 1,0.10<\/b><\/span><\/span><\/span>5<\/b><\/span><\/span><\/sup><\/span>\u00a0N\/m<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>, a acelera\u00e7\u00e3o da gravidade \u00e9 10 m\/s\u00b2\u00a0<\/b><\/span><\/span><\/span>e que a\u00a0<\/b><\/span><\/span>densidade da \u00e1gua\u00a0<\/b><\/span><\/span><\/span>seja constante e igual a\u00a0<\/b><\/span><\/span>1,0.10\u00b3 kg\/m\u00b3.\u00a0<\/b><\/span><\/span><\/span>Com base nos<\/b><\/span><\/span><\/p>\n

conceitos de hidrost\u00e1tica<\/b><\/span><\/span><\/span>, assinale a alternativa que indica\u00a0<\/b><\/span><\/span>quantas vezes a press\u00e3o externa da \u00e1gua sobre o submarino, naquela profundidade, \u00e9 maior que a press\u00e3o no seu interior, se o submarino repousa no fundo do plat\u00f4.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

15-(UFSM-RS-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O\u00a0<\/b><\/span><\/span>mergulho profundo\u00a0<\/b><\/span><\/span><\/span>pode causar problemas de sa\u00fade ao mergulhador devido \u00e0\u00a0<\/b><\/span><\/span>alta press\u00e3o<\/b><\/span><\/span><\/span>. Num<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

mar de \u00e1guas calmas<\/b><\/span><\/span><\/span>,<\/b><\/span><\/span><\/p>\n

I – a press\u00e3o sobre o mergulhador aumenta aproximadamente 1 atm a cada 10m de profundidade.<\/b><\/span><\/span><\/p>\n

II – o m\u00f3dulo da for\u00e7a de empuxo que atua sobre o mergulhador cresce linearmente com a profundidade.<\/b><\/span><\/span><\/p>\n

III – a diferen\u00e7a de press\u00e3o entre os p\u00e9s e a cabe\u00e7a do mergulhador, num mergulho vertical, \u00e9<\/b><\/span><\/span><\/p>\n

praticamente independente da profundidade.<\/b><\/span><\/span><\/p>\n

Est\u00e1(\u00e3o) correta(s)<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

16-(UNEAL-AL-014)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O procedimento adotado para\u00a0<\/b><\/span><\/span>medir a press\u00e3o de uma amostra de g\u00e1s<\/b><\/span><\/span><\/span>\u00a0em um<\/b><\/span><\/span><\/p>\n

laborat\u00f3rio, onde o m\u00f3dulo da acelera\u00e7\u00e3o\u00a0<\/b><\/span><\/span>da gravidade \u00e9 10m\/s<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>, est\u00e1 esquematizado<\/b><\/span><\/span><\/p>\n

nas figuras.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

Na\u00a0<\/b><\/span><\/span>figura I<\/b><\/span><\/span><\/span>, um\u00a0<\/b><\/span><\/span>reservat\u00f3rio, R, cheio de g\u00e1s, encontra-se ligado a um man\u00f4metro de tubo aberto contendo merc\u00fario de densidade 13,6g\/cm<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>e<\/b><\/span><\/span><\/span>, na\u00a0<\/b><\/span><\/span>figura II, um tubo capilar\u00a0<\/b><\/span><\/span><\/span>com a sua extremidade\u00a0<\/b><\/span><\/span>superior fechada\u00a0<\/b><\/span><\/span><\/span>est\u00e1 mergulhado em um recipiente aberto contendo\u00a0<\/b><\/span><\/span>merc\u00fario.<\/b><\/span><\/span><\/span><\/p>\n

Nessas condi\u00e7\u00f5es, a\u00a0<\/b><\/span><\/span>press\u00e3o exercida pelo g\u00e1s, em 10<\/b><\/span><\/span><\/span>5<\/b><\/span><\/span><\/sup><\/span>\u00a0pascal<\/b><\/span><\/span><\/span>, \u00e9 de, aproximadamente,<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

 <\/p>\n

Densidade e press\u00e3o<\/b><\/span><\/span><\/span><\/p>\n

47-(UEM-PR-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Analise as alternativas abaixo e assinale o que for correto.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

01) No Sistema Internacional de Unidades, a unidade de densidade volum\u00e9trica \u00e9 o kg\/m<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>.<\/b><\/span><\/span><\/p>\n

02) A press\u00e3o \u00e9 uma grandeza escalar.<\/b><\/span><\/span><\/p>\n

04) A diferen\u00e7a de press\u00e3o entre dois pontos no interior de um l\u00edquido homog\u00eaneo em repouso \u00e9 proporcional \u00e0 diferen\u00e7a da altura entre esses dois pontos.<\/b><\/span><\/span><\/p>\n

08) A press\u00e3o que uma for\u00e7a exerce sobre um objeto \u00e9 diretamente proporcional \u00e0 \u00e1rea sobre a qual a for\u00e7a \u00e9 aplicada.<\/b><\/span><\/span><\/p>\n

16) Quando um corpo \u00e9 imerso em um l\u00edquido, uma for\u00e7a, na dire\u00e7\u00e3o vertical, \u00e9 exercida sobre o corpo, e o m\u00f3dulo dessa for\u00e7a \u00e9 diretamente proporcional ao volume do l\u00edquido deslocado<\/b><\/span><\/span><\/p>\n

 <\/p>\n

48-(PUC-RJ-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um recipiente cont\u00e9m 0,0100 m<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>\u00a0de \u00e1gua e 2000 cm<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>\u00a0de \u00f3leo. Considerando-se a densidade da \u00e1gua <\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

1,00 g\/cm<\/b><\/span><\/span>3\u00a0<\/b><\/span><\/span><\/sup>e a densidade do \u00f3leo 0,900 g\/cm<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>, a massa, medida em<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/sup>quilogramas, da mistura destes l\u00edquidos \u00e9:<\/b><\/span><\/span><\/p>\n

(A) 11,8\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0(B) 101,8\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 (C) 2,8\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 (D) 28\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 (E) 118<\/b><\/span><\/span><\/p>\n

 <\/p>\n

Teorema de Stevin \u2013 press\u00e3o hidrost\u00e1tica – vasos comunicantes<\/b><\/span><\/span><\/span><\/p>\n

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

37-(UNESP-SP-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O relevo submarino de determinada regi\u00e3o est\u00e1 representado pelas curvas de n\u00edvel mostradas na figura, na qual os valores em metros representam as alturas verticais medidas em rela\u00e7\u00e3o ao n\u00edvel de refer\u00eancia mais profundo, mostrado pela linha vermelha.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

Dois peixes, 1 e 2, est\u00e3o inicialmente em repouso nas posi\u00e7\u00f5es indicadas e deslocam-se para o ponto P, onde param novamente. Considere que toda a regi\u00e3o mostrada na figura esteja submersa, que a \u00e1gua do mar esteja em equil\u00edbrio e que sua densidade seja igual a 10<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>\u00a0kg\/m<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>. Se g = 10 m\/s<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sup>\u00a0e 1 atm = 10<\/b><\/span><\/span>5\u00a0<\/b><\/span><\/span><\/sup>Pa, pode-se afirmar, considerando-se apenas os pontos de partida e de chegada, que, durante seu movimento, o peixe<\/b><\/span><\/span><\/p>\n

(A) 2 sofreu uma redu\u00e7\u00e3o de press\u00e3o de 3 atm.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 (B) 1 sofreu um aumento de press\u00e3o de 4 atm.<\/b><\/span><\/span><\/p>\n

(C) 1 sofreu um aumento de press\u00e3o de 6 atm.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 (D) 2 sofreu uma redu\u00e7\u00e3o de press\u00e3o de 6 atm.<\/b><\/span><\/span><\/p>\n

(E) 1 sofreu uma redu\u00e7\u00e3o de press\u00e3o de 3 atm.<\/b><\/span><\/span><\/p>\n

 <\/p>\n

38-(ENEM-MEC-012)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O manual que acompanha uma ducha higi\u00eanica informa que a press\u00e3o m\u00ednima da \u00e1gua para o seu funcionamento apropriado \u00e9 de 20 kPa. A figura mostra a instala\u00e7\u00e3o hidr\u00e1ulica com a caixa d\u2019\u00e1gua e o cano ao qual deve ser conectada a ducha.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

O valor da press\u00e3o da \u00e1gua na ducha est\u00e1 associado \u00e0 altura<\/b><\/span><\/span><\/p>\n

a) h<\/b><\/span><\/span>1<\/b><\/span><\/span><\/sub>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0b h<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sub>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c) h<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sub>\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 d h<\/b><\/span><\/span>4<\/b><\/span><\/span><\/sub>\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 e h<\/b><\/span><\/span>5<\/b><\/span><\/span><\/sub><\/p>\n

 <\/p>\n

 <\/p>\n

Experi\u00eancia de Torricelli<\/b><\/span><\/span><\/span><\/p>\n

 <\/p>\n

35-(UNESP-SP-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Seis reservat\u00f3rios cil\u00edndricos, superiormente abertos e id\u00eanticos (A, B, C, D, E e F) est\u00e3o apoiados sobre uma superf\u00edcie horizontal plana e ligados por v\u00e1lvulas (V) nas posi\u00e7\u00f5es indicadas na figura.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

Com as v\u00e1lvulas (V) fechadas, cada reservat\u00f3rio cont\u00e9m \u00e1gua at\u00e9 o n\u00edvel (h) indicado na figura. Todas as v\u00e1lvulas s\u00e3o, ent\u00e3o, abertas, o que permite a passagem livre da \u00e1gua entre os reservat\u00f3rios, at\u00e9 que se estabele\u00e7a o equil\u00edbrio hidrost\u00e1tico. Nesta situa\u00e7\u00e3o final, o n\u00edvel da \u00e1gua, em dm, ser\u00e1 igual a<\/b><\/span><\/span><\/p>\n

(A) 6,0 nos reservat\u00f3rios de A a E e 3,0 no reservat\u00f3rio F.<\/b><\/span><\/span><\/p>\n

(B) 5,5 nos reservat\u00f3rios de A a E e 3,0 no reservat\u00f3rio F.<\/b><\/span><\/span><\/p>\n

(C) 6,0 em todos os reservat\u00f3rios.<\/b><\/span><\/span><\/p>\n

(D) 5,5 em todos os reservat\u00f3rios.<\/b><\/span><\/span><\/p>\n

(E) 5,0 nos reservat\u00f3rios de A a E e 3,0 no reservat\u00f3rio F.<\/b><\/span><\/span><\/p>\n

 <\/p>\n

 <\/p>\n

Princ\u00edpio de Pascal<\/b><\/span><\/span><\/span><\/p>\n

 <\/p>\n

25-UERJ-RJ-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Observe, na figura a seguir, a representa\u00e7\u00e3o de uma prensa hidr\u00e1ulica, na qual as for\u00e7as F<\/b><\/span><\/span>1<\/b><\/span><\/span><\/sub>\u00a0e F<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sub>\u00a0atuam, respectivamente, sobre os \u00eambolos dos cilindros I e II.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

Admita que os cilindros estejam totalmente preenchidos por um l\u00edquido.<\/b><\/span><\/span><\/p>\n

O volume do cilindro II \u00e9 igual a quatro vezes o volume do cilindro I, cuja altura \u00e9 o triplo da altura do cilindro II.<\/b><\/span><\/span><\/p>\n

A raz\u00e3o F<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sub>\/F<\/b><\/span><\/span>1<\/b><\/span><\/span><\/sub>\u00a0entre as intensidades das for\u00e7as, quando o sistema est\u00e1 em equil\u00edbrio, corresponde a:<\/b><\/span><\/span><\/p>\n

(A) 12\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 (B) 6\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 (C) 3\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 (D) 2<\/b><\/span><\/span><\/p>\n

 <\/p>\n

26-(ESPCEX-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um elevador hidr\u00e1ulico de um posto de gasolina \u00e9 acionado por um pequeno \u00eambolo de \u00e1rea igual a \u00a04.10<\/b><\/span><\/span>-4\u00a0<\/b><\/span><\/span><\/sup>m<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sup>.<\/b><\/span><\/span><\/p>\n

O autom\u00f3vel a ser elevado tem peso de 2.10<\/b><\/span><\/span>4<\/b><\/span><\/span><\/sup>N e est\u00e1 sobre o \u00eambolo maior de \u00e1rea 0,16m<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sup>.<\/b><\/span><\/span><\/p>\n

A intensidade m\u00ednima da for\u00e7a que dever ser aplicada ao \u00eambolo menor para conseguir elevar o autom\u00f3vel \u00e9 de<\/b><\/span><\/span><\/p>\n

a)\u00a0 20 N \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0b)\u00a0 40 N \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0c)\u00a0 50 N \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0d)\u00a0 80 N \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0e)\u00a0 120 N<\/b><\/span><\/span><\/p>\n

 <\/p>\n

27-(UNESP-SP-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O sif\u00e3o \u00e9 um dispositivo que permite transferir um l\u00edquido de um recipiente mais alto para outro mais baixo, por meio, por exemplo, de uma mangueira cheia do mesmo l\u00edquido. Na figura, que representa, esquematicamente, um sif\u00e3o utilizado para transferir \u00e1gua de um recipiente sobre uma mesa para outro no piso, R \u00e9 um registro que, quando fechado, impede o movimento da \u00e1gua. Quando o registro \u00e9 aberto, a diferen\u00e7a de press\u00e3o entre os pontos A e B provoca o escoamento da \u00e1gua para o recipiente de baixo.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

Considere que os dois recipientes estejam abertos para a atmosfera, que a densidade da \u00e1gua seja igual a 10<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>\u00a0kg\/m<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup><\/p>\n

e que g = 10 m\/s<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sup>. De acordo com as medidas indicadas na figura, com o registro R fechado, a diferen\u00e7a de press\u00e3o<\/b><\/span><\/span><\/p>\n

P<\/b><\/span><\/span>A<\/b><\/span><\/span><\/sub>\u00a0– P<\/b><\/span><\/span>B<\/b><\/span><\/span><\/sub>, entre os pontos A e B, em pascal, \u00e9 igual a<\/b><\/span><\/span><\/p>\n

(A) 4000.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 (B) 10000.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 (C) 2000.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0(D) 8000.\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 (E) 12000<\/b><\/span><\/span><\/p>\n

 <\/p>\n

 <\/p>\n

Teorema de Arquimedes \u2013 Empuxo<\/b><\/span><\/span><\/span><\/p>\n

 <\/p>\n

67-(UNIFESP-SP-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um objeto maci\u00e7o cil\u00edndrico, de di\u00e2metro igual a 2,0 cm, \u00e9 composto de duas partes cil\u00edndricas distintas, unidas por uma cola de massa desprez\u00edvel. A primeira parte, com 5,0 cm de altura, \u00e9 composta por uma corti\u00e7a com densidade volum\u00e9trica 0,20 g\/cm<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>.<\/b><\/span><\/span><\/p>\n

A segunda parte, de 0,5 cm de altura, \u00e9 composta por uma liga met\u00e1lica de densidade volum\u00e9trica 8,0 g\/cm<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>. Conforme indica a figura, o objeto encontra-se em repouso, parcialmente submerso na \u00e1gua, cuja densidade volum\u00e9trica \u00e9 1,0 g\/cm<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

Nas condi\u00e7\u00f5es descritas relativas ao equil\u00edbrio mec\u00e2nico do objeto e considerando \u03c0 aproximadamente igual a 3, determine:<\/b><\/span><\/span><\/p>\n

a) a massa total, em gramas, do objeto cil\u00edndrico.<\/b><\/span><\/span><\/p>\n

b) a altura, em cent\u00edmetros, da parte do cilindro submerso na \u00e1gua.<\/b><\/span><\/span><\/p>\n

 <\/p>\n

68-(UFV-MG-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Para poder emergir e submergir (afundar), um submarino utiliza tanques de lastro. Esses tanques ficam vazios quando o submarino est\u00e1 na superf\u00edcie da \u00e1gua e se enchem de \u00e1gua do mar, de modo a permitir sua submers\u00e3o. <\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

As figuras A, B e C ilustram, respectivamente, situa\u00e7\u00f5es em que um submarino encontra-se na superf\u00edcie, submergindo e totalmente submerso. Sabendo que a \u00e1gua do mar tem densidade de aproximadamente 1000 kg\/m<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>, que o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/sup>volume de um submarino \u00e9 de 1500 m<\/b><\/span><\/span>3\u00a0<\/b><\/span><\/span><\/sup>e quesua massa (sem lastro) \u00e9 de<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/sup>1300 ton (toneladas), o volume de \u00e1gua<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/sup>necess\u00e1rio para que o submarino permane\u00e7a<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/sup>totalmente submerso e em equil\u00edbrio \u00e9 igual a:<\/b><\/span><\/span><\/p>\n

a) 300 m<\/b><\/span><\/span>3\u00a0<\/b><\/span><\/span><\/sup>\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\u00a0b) 200 m<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>\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 c) 500 m<\/b><\/span><\/span>3\u00a0<\/b><\/span><\/span><\/sup>\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\u00a0d) 100 m<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup><\/p>\n

 <\/p>\n

69-(UFV-MG-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

As medidas aproximadas do transatl\u00e2ntico Costa Conc\u00f3rdia, que colidiu recentemente com uma pedra s\u00e3o:<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

massa de 1,2.10<\/b><\/span><\/span>8<\/b><\/span><\/span><\/sup>kg, comprimento de 300 m, largura de 40 m e altura de 60 m. Supondo que o formato do navio seja o de um paralelep\u00edpedo, podemos estimar a profundidade m\u00ednima que o mar deve possuir para que o navio possa flutuar livremente. Considerando que o m\u00f3dulo da acelera\u00e7\u00e3o gravitacional \u00e9 10 m\/s<\/b><\/span><\/span>2<\/b><\/span><\/span><\/sup>\u00a0e a densidade da \u00e1gua do mar como sendo de 1 g\/cm<\/b><\/span><\/span>3<\/b><\/span><\/span><\/sup>, \u00e9 CORRETO afirmar que essa profundidade m\u00ednima \u00e9:<\/b><\/span><\/span><\/p>\n

a) 10,0 m\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 b) 50,0 m\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 c) 06,7 m\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 d) 53,3 m\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/p>\n

 <\/p>\n

70-(UFRN-RN-013)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um bal\u00e3o de ar quente \u00e9 constitu\u00eddo por um \u00a0saco de tecido sint\u00e9tico, chamado envelope, o qual \u00e9 capaz de conter ar aquecido.<\/b><\/span><\/span><\/p>\n

Embaixo do envelope, h\u00e1 um cesto de vime, para o transporte de passageiros, e uma fonte de calor, conforme ilustra a figura a seguir.<\/b><\/span><\/span><\/p>\n

\"Hidrost\u00e1tica\"<\/p>\n

Para que o bal\u00e3o suba, aquece-se\u00a0 o ar no interior do envelope e, com isso, inicia-se\u00a0 a flutua\u00e7\u00e3o do bal\u00e3o.\u00a0 Essa flutua\u00e7\u00e3o ocorre porque, com o aquecimento\u00a0 do ar no\u00a0 interior do envelope,<\/b><\/span><\/span><\/p>\n

A) a densidade do ar\u00a0 diminui, tornando o peso do bal\u00e3o menor que o empuxo.<\/b><\/span><\/span><\/p>\n

B) a press\u00e3o externa do ar sobre o bal\u00e3o aumenta, tornando seu peso menor que o empuxo.<\/b><\/span><\/span><\/p>\n

C) a densidade do ar diminui, tornando o peso do bal\u00e3o maior que o empuxo.<\/b><\/span><\/span><\/p>\n

D) a press\u00e3o externa do ar sobre o bal\u00e3o aumenta, tornando seu peso maior que o empuxo.<\/b><\/span><\/span><\/span><\/p>\n

 <\/p>\n

Confira as resolu\u00e7\u00f5es comentadas<\/span><\/a><\/h3>\n

 <\/p>\n

Clique aqui para ver sobre o tema!<\/a><\/p>\n

Confira as v\u00eddeo aulas!<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

HIDROST\u00c1TICA \u2013 2013 – 2014 01-(FUVEST-SP-014) Um bloco de madeira\u00a0imperme\u00e1vel,\u00a0de massa\u00a0M\u00a0e dimens\u00f5es 2x3x3cm3, \u00e9 inserido muito lentamente na \u00e1gua de um balde, at\u00e9 a condi\u00e7\u00e3o de\u00a0equil\u00edbrio, com\u00a0metade de seu volume submersa. A\u00a0\u00e1gua\u00a0que vaza do balde \u00e9 coletada e num copo e\u00a0tem massa m.\u00a0A figura ilustra as situa\u00e7\u00f5es inicial e final; em\u00a0ambos os casos, o balde encontra-se cheio de \u00e1gua at\u00e9<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3123,"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-3278","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3278","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=3278"}],"version-history":[{"count":4,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3278\/revisions"}],"predecessor-version":[{"id":9888,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3278\/revisions\/9888"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3123"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=3278"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}