{"id":688,"date":"2015-05-12T18:07:53","date_gmt":"2015-05-12T18:07:53","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=688"},"modified":"2024-09-03T12:47:54","modified_gmt":"2024-09-03T12:47:54","slug":"resolucao-comentada-da-ufsc-2015-2","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/universidades-2015\/exercicios-resolvidos-da-ufsc-2015-2\/resolucao-comentada-da-ufsc-2015-2\/","title":{"rendered":"Resolu\u00e7\u00e3o Comentada da UFSC 2015 – 2"},"content":{"rendered":"

RESOLU\u00c7\u00d5ES<\/b><\/span><\/span><\/span><\/p>\n

01- 01. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— a<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>energia cin\u00e9tica<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>(<\/b><\/span><\/span>Ec=mV<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\/2<\/b><\/span><\/span>) depende da<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>velocidade<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>do dardo — no ponto<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>mais alto<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>da trajet\u00f3ria a<\/b><\/span><\/span>velocidade vertical \u00e9 nula<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>mas existe<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>a velocidade horizontal que \u00e9 constante durante todo o movimento.<\/b><\/span><\/p>\n

02. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— a<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>velocidade de lan\u00e7amento \u00e9<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>V=25m\/s<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>e, nesse instante<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>E<\/b><\/span><\/span>c<\/b><\/span><\/sub><\/span>=mV<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\/2<\/b><\/span><\/span>=0,8.625\/2<\/b><\/span><\/span>=250J<\/b><\/span><\/span>, que<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>independe<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>do \u00e2ngulo de lan\u00e7amento.<\/b><\/span><\/span><\/p>\n

04. Falsa —<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>na<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>altura m\u00e1xima<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>V<\/b><\/span><\/span>y<\/b><\/span><\/sub><\/span>=o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>v<\/b><\/span><\/span>oy<\/b><\/span><\/sub><\/span>=V<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>.sen30<\/b><\/span><\/span>o<\/b><\/span><\/sup><\/span>=25.0,5 —<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>V<\/b><\/span><\/span>oy<\/b><\/span><\/sub><\/span>=12,5m\/s<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>V<\/b><\/span><\/span>y<\/b><\/span><\/sub><\/span>2<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>= V<\/b><\/span><\/span>oy<\/b><\/span><\/sub><\/span>2<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>\u2013 2.g.h<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span><\/p>\n

0<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>= 12,5<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>\u2013 2.10.h —<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>h<\/b><\/span><\/span>max<\/b><\/span><\/sub><\/span>=156.25=7,81m.<\/b><\/span><\/span><\/p>\n

08. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— n\u00e3o depende da<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>massa<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>do dardo.<\/b><\/span><\/span><\/p>\n

16. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— o dardo \u00e9 considerado um ponto material e os<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>atritos s\u00e3o desprezados<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>e a for\u00e7a peso \u00e9 uma for\u00e7a conservativa.<\/b><\/span><\/span><\/p>\n

Soma (02 + 16)=18<\/b><\/span><\/span><\/p>\n

02- O1. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— possui<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>maior \u00e1rea de contato<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>com o solo oferecendo mais estabilidade para caminhar.<\/b><\/span><\/span><\/p>\n

02. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— o salto alto<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>desloca o peso<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>e consequentemente o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>centro de gravidade<\/b><\/span>. Veja figura<\/b><\/span><\/span><\/p>\n

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

\"\"<\/p>\n

04. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— veja 02.<\/b><\/span><\/span><\/p>\n

08. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— com<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>salto o peso \u00e9 deslocado para a frente<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>e<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>sem salto, num plano inclinado o peso<\/b><\/span><\/p>\n

\"\"<\/p>\n

tamb\u00e9m \u00e9 deslocado para a frente.<\/b><\/span><\/p>\n

16. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>press\u00e3o=for\u00e7a (no caso, o peso)\/\u00e1rea de contato com o solo) —<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>P=P\/S<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>— observe que a<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>press\u00e3o P \u00e9 inversamente proporcional \u00e0 \u00e1rea de contato<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>— com o sapato B,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>S \u00e9 menor, e a press\u00e3o sobre o solo \u00e9 maior.<\/b><\/span><\/p>\n

Soma (01 + 02 + 08)= 11<\/b><\/span><\/span><\/p>\n

03- 01. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— A cor que percebemos depende da<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>temperatura de cor das fontes de ilumina\u00e7\u00e3o<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>que iluminam a cena observada. A<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>luz branca neutra fornecida na tabela<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>\u00e9 tomada como padr\u00e3o e possui<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

temperatura de cor<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>de 4000K<\/b><\/span><\/span>. Quanto<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>mais elevada \u00e9 a temperatura de cor de uma luz, maior percentagem de azuis ter\u00e1<\/b><\/span>.<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>As luzes de baixa temperatura, pelo contr\u00e1rio ter\u00e3o uma alta percentagem de radia\u00e7\u00f5es vermelhas, que \u00e9 o caso das l\u00e2mpadas incandescentes e devem possuir temperatura de cor menor que 4000K.<\/b><\/span><\/span><\/p>\n

02. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— se o objeto for iluminado por<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>luz azul<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>ele<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>refletir\u00e1<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>preponderantemente a<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>luz azul<\/b><\/span>, se por<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

luz vermelha<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>refletir\u00e1<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>preponderantemente a<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>luz vermelha<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>e assim por diante. (veja figuras acima).<\/b><\/span><\/span><\/p>\n

04. Falsa.<\/b><\/span><\/p>\n

08. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— o rendimento da l\u00e2mpada incandescente \u00e9 minimo: apenas o equivalente a 5% da energia el\u00e9trica consumida \u00e9 transformado em\u00a0<\/b><\/span><\/span>luz<\/b><\/span><\/span><\/span><\/a>, os outros 95% s\u00e3o transformados em\u00a0<\/b><\/span><\/span>calor<\/b><\/span><\/span><\/span><\/a>.<\/b><\/span><\/span><\/p>\n

16. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— As\u00a0<\/b><\/span><\/span>l\u00e2mpadas<\/b><\/span><\/span><\/span><\/a>\u00a0fluorescentes funcionam de modo semelhante aos tubos de descarga de g\u00e1s n\u00e9on, possuem um par de<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>el\u00e9trodos<\/b><\/span><\/span><\/span><\/a>\u00a0em cada extremo. O tubo de vidro \u00e9 coberto com um material \u00e0 base de\u00a0<\/b><\/span><\/span>f\u00f3sforo<\/b><\/span><\/span><\/span><\/a>. Este, quando excitado com<\/b><\/span><\/span>radia\u00e7\u00e3o ultravioleta<\/b><\/span><\/span><\/span><\/a>\u00a0gerada pela\u00a0<\/b><\/span><\/span>ioniza\u00e7\u00e3o<\/b><\/span><\/span><\/span><\/a>\u00a0dos gases, produz\u00a0<\/b><\/span><\/span>luz vis\u00edvel<\/b><\/span><\/span><\/span><\/a>.<\/b><\/span><\/span><\/p>\n

32- Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>1 lumin\u00e1ria<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>20 anos=20x360diasx24h=172800h<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>— energia nesse tempo —<\/b><\/span><\/span>W=P.t<\/b><\/span><\/span>=0,13kWx172800h=<\/b><\/span><\/span>22464kWh.<\/b><\/span><\/span><\/p>\n

Cada kWh custa 0,30<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>ent\u00e3o o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>custo total de uma lumin\u00e1ria<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>ser\u00e1 —<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>C$=<\/b><\/span><\/span>22464×0,30=<\/b><\/span><\/span>6739,20.<\/b><\/span><\/span><\/p>\n

Como s\u00e3o 210 lumin\u00e1rias voc\u00ea ter\u00e1 o custo total final — C$=210×6739,20=1. 415.232,00.<\/b><\/span><\/span><\/p>\n

Como foram investidos C$1.600.000, ser\u00e3o necess\u00e1rios mais de 20 anos.<\/b><\/span><\/span><\/p>\n

Soma (01 + 32)= 33<\/b><\/span><\/span><\/p>\n

04- 01. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— se os<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>pneus aquecem<\/b><\/span><\/span>, a<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>press\u00e3o interna aumenta<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>e, portanto<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>n\u00e3o \u00e9 uma isob\u00e1rica que ocorre \u00e0 press\u00e3o constante.<\/b><\/span><\/p>\n

02. Correto<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— veja 01.<\/b><\/span><\/span><\/p>\n

04. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— a quantidade<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>de ar<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>dentro dele<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>varia.<\/b><\/span><\/p>\n

08. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>PV=nRT<\/b><\/span>, onde n e R s\u00e3o constantes.<\/b><\/span><\/span><\/p>\n

16. Falsa<\/b><\/span><\/p>\n

32- Correta<\/b><\/span>.<\/b><\/span><\/span><\/p>\n

Soma (02 + 08 + 32)= 42.<\/b><\/span><\/span><\/p>\n

05- 01. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— entre 2s e 4s, pelo gr\u00e1fico,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>i=1 A<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>i=Q\/t<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— 1=Q\/(4 \u2013 2) —<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Q=2C.<\/b><\/span><\/span><\/p>\n

02. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>regra da m\u00e3o direita<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>polegar no sentido da corrente (entrando na folha)<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>e o as<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>linhas de campo magn\u00e9tico tem o sentido da \u201cfechada\u201d da m\u00e3o.<\/b><\/span><\/span><\/p>\n

04. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>os el\u00e9trons, em um circuito no qual h\u00e1 uma corrente el\u00e9trica cont\u00ednua<\/b><\/span>, movem-se com<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>velocidade muito pequena (apenas 0,1 mm\/s, aproximadamente<\/b><\/span><\/span>). Entretanto, quando ligamos o interruptor do circuito, o campo el\u00e9trico que surge no condutor \u00e9 estabelecido quase instantaneamente em todo fio, pois a velocidade de propaga\u00e7\u00e3o desse campo \u00e9 praticamente igual \u00e0 da luz. Ent\u00e3o, em um tempo muito curto, todos os el\u00e9trons livres j\u00e1 est\u00e3o em movimento, embora os el\u00e9trons que come\u00e7aram a mover-se nas proximidades do interruptor s\u00f3 alcancem o filamento depois de um tempo muito longo.<\/b><\/span><\/span><\/p>\n

\u00a0<\/span>08. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>entre 2s e 6s — i=1 A<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>i=Q\/t<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>— 1 = Q\/(6 \u2013 2) —<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Q=4C<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Q=n.e<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>— 4=n.1,6.10<\/b><\/span><\/span>-19<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>— n=4\/1,6.10<\/b><\/span><\/span>-19<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>n=2,5.10<\/b><\/span><\/span>19<\/b><\/span><\/sup><\/span>el\u00e9trons.<\/b><\/span><\/span><\/p>\n

16. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>campo el\u00e9trico tem dire\u00e7\u00e3o tangente \u00e0 trajet\u00f3ria e sentido contr\u00e1rio ao do campo<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>magn\u00e9tico,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>pois q<0 (el\u00e9trons).<\/b><\/span><\/span><\/p>\n

32. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>B=\u03bc<\/b><\/span><\/span>o<\/b><\/span><\/sub><\/span>.i\/2\u03c0d<\/b><\/span><\/span>=4\u03c0.10<\/b><\/span><\/span>-7<\/b><\/span><\/sup><\/span>.1\/2\u03c01 —<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>B=2.10<\/b><\/span><\/span>-7<\/b><\/span><\/sup><\/span>T.<\/b><\/span><\/span><\/p>\n

64. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>a<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>carga Q \u00e9 fornecida pela \u00e1rea da figura compreendida entre 0 e 6s (trap\u00e9zio)<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Q=(B +<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>b).h\/2<\/b><\/span><\/span>=(6 + 4).1\/2<\/b><\/span><\/span>=5C<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>i<\/b><\/span><\/span>m<\/b><\/span><\/sub><\/span>=Q\/t<\/b><\/span><\/span>=5\/6=<\/b><\/span><\/span>0,8 A.<\/b><\/span><\/span><\/p>\n

Soma (2 + 8 + 32)=42<\/b><\/span><\/span><\/p>\n

06- 01. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— veja figura e f\u00f3rmulas abaixo abaixo e observe que no interior do tanque o potencial el\u00e9trico \u00e9 constante e diferente de zero.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

02. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>possui cargas el\u00e9tricas<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>mas como est\u00e1 neutro as<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>cargas positivas anulam as cargas negativas.<\/b><\/span><\/span><\/p>\n

04. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>campo el\u00e9trico — E=kQ\/d<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>=9.10<\/b><\/span><\/span>9<\/b><\/span><\/sup><\/span>.270.10<\/b><\/span><\/span>-6<\/b><\/span><\/sup><\/span>\/200<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>=2430.10<\/b><\/span><\/span>3<\/b><\/span><\/sup><\/span>\/4.10<\/b><\/span><\/span>4<\/b><\/span><\/sup><\/span>=607,5.10<\/b><\/span><\/span>-1<\/b><\/span><\/sup><\/span>=<\/b><\/span><\/span>60,75N\/C.<\/b><\/span><\/span><\/p>\n

08. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>aterramento significa ligar o caminh\u00e3o-tanque ao solo por um material condutor<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>de modo que as<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>cargas el\u00e9tricas escoem para o solo, mantendo-o neutro.<\/b><\/span><\/span><\/p>\n

16. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>veja gr\u00e1ficos da 01<\/b><\/span><\/span>. Como<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>cargas el\u00e9tricas de mesmo sinal se repelem<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>e o material do caminh\u00e3o tanque \u00e9 met\u00e1lico (condutor) as cargas el\u00e9tricas se<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>localizam na superf\u00edcie externa do mesmo tendendo a ficar o mais longe poss\u00edvel..<\/b><\/span><\/span><\/p>\n

Soma (08 + 16)=24<\/b><\/span><\/span><\/p>\n

07- 01. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— s<\/b><\/span><\/span>e um corpo<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span><\/span>estiver flutuando parcialmente<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span><\/span>imerso<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span><\/span>num l\u00edquido, a for\u00e7a resultante sobre ele \u00e9 nula (equil\u00edbrio vertical)\u00a0<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—\u00a0 P = E\u00a0 — d<\/b><\/span><\/span><\/span>c<\/b><\/span><\/span><\/sub><\/span>.V<\/b><\/span><\/span><\/span>total<\/b><\/span><\/span><\/sub><\/span>.g=d<\/b><\/span><\/span><\/span>l\u00edquido<\/b><\/span><\/span><\/sub><\/span>.V<\/b><\/span><\/span><\/span>imerso<\/b><\/span><\/span><\/sub><\/span>.g\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>d<\/b><\/span><\/span><\/span>corpo<\/b><\/span><\/span><\/sub><\/span>\/d<\/b><\/span><\/span><\/span>l\u00edquido<\/b><\/span><\/span><\/sub><\/span>=V<\/b><\/span><\/span><\/span>imerso<\/b><\/span><\/span><\/sub><\/span>\/V<\/b><\/span><\/span><\/span>tota<\/b><\/span><\/span><\/sub><\/span>l<\/b><\/span><\/span><\/sub><\/span><\/p>\n

V<\/b><\/span><\/span>corpo<\/b><\/span><\/sub><\/span>=2×0,45×6=5,4m<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>0,05\/1 = V<\/b><\/span><\/span>imerso<\/b><\/span><\/sub><\/span>\/5,4<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>— V<\/b><\/span><\/span>imerso<\/b><\/span><\/sub><\/span>=0,27 —<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>V<\/b><\/span><\/span>imerso<\/b><\/span><\/sub><\/span>=S.h=2×0,45xh<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>— 0,27 = 0,9.h —<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>h=<\/b><\/span><\/span>0,27\/0,9<\/b><\/span><\/span>=0,3m<\/b><\/span><\/span>.<\/b><\/span><\/span><\/p>\n

02. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— a rela\u00e7\u00e3o \u00e9 entre as<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>densidades do corpo e da \u00e1gua<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>o mais denso que a \u00e1gua afunda e o menos denso flutua.<\/b><\/span><\/span><\/p>\n

04. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— veja 02.<\/b><\/span><\/span><\/p>\n

08. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>empuxo sobre a prancha<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>E=d<\/b><\/span><\/span>\u00e1gua<\/b><\/span><\/sub><\/span>.g.V=<\/b><\/span><\/span>1.10.5,4=<\/b><\/span><\/span>54N<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>peso de Pedro e Thiago<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>P=mg<\/b><\/span><\/span>=103.10=<\/b><\/span><\/span>1030N<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>o peso dos dois \u00e9 maior que o empuxo sobre a prancha,<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>ent\u00e3o afundam.<\/b><\/span><\/span><\/p>\n

16. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Causa do empuxo\u00a0\u2013 Devido ao teorema de<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Stevin, P=d<\/b><\/span><\/span>l\u00edquido<\/b><\/span><\/sub><\/span>.g.h,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>para um mesmo l\u00edquido,<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>quanto maior a profundidade, maior ser\u00e1 a press\u00e3o<\/b><\/span><\/span>. Observe na figura abaixo, onde a esfera<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

est\u00e1 imersa, que as<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>for\u00e7as exercidas pelo\u00a0l\u00edquido sobre ela s\u00e3o maiores nas \u00e1reas inferiores (onde h \u00e9 maior) que nas superiores (onde h \u00e9 menor). A for\u00e7a resultante de todas essas for\u00e7as est\u00e1 dirigida para cima, e corresponde ao empuxo que age sobre essa esfera.<\/b><\/span><\/p>\n

Soma (01 + 04 + 16)=21<\/b><\/span><\/span><\/p>\n

08- 01. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>faixa m\u00e9dia de freq\u00fc\u00eancias aud\u00edveis para um ouvido humano normal varia de 20Hz \u00a0at\u00e9 20.000Hz.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

Ondas com freq\u00fc\u00eancias inferiores a 20Hz s\u00e3o os infra-sons e superiores a 20.000Hz s\u00e3o os ultra-sons.<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>As ondas infra-s\u00f4nicas e ultra-s\u00f4nicas n\u00e3o s\u00e3o aud\u00edveis pelo ouvido humano.<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>Os ultra-sons podem ser ouvidos por certos animais como morcego e o c\u00e3o e tamb\u00e9m utilizados na medicina (ecocardiografia, ultra-sonografia obst\u00e9trica, etc) .<\/b><\/span><\/span><\/p>\n

02. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— pelo enunciado uma pessoa em conversa normal emite P=10<\/b><\/span><\/span>-5<\/b><\/span><\/sup><\/span>W — ent\u00e3o, 400.000 = 4.10<\/b><\/span><\/span>5<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>emitir\u00e3o —<\/b><\/span><\/span>P<\/b><\/span><\/span>t<\/b><\/span><\/sub><\/span>=4.10<\/b><\/span><\/span>5<\/b><\/span><\/sup><\/span>.10<\/b><\/span><\/span>-5<\/b><\/span><\/sup><\/span>=4W<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>P<\/b><\/span><\/span>l\u00e2mpada<\/b><\/span><\/sub><\/span>=100\/24<\/b><\/span><\/span>=4W.<\/b><\/span><\/span><\/p>\n

04. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— podem ouvir — veja 01.<\/b><\/span><\/span><\/p>\n

08. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— ondas sonoras s\u00e3o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>ondas mec\u00e2nicas longitudinais.<\/b><\/span><\/span><\/p>\n

16. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— NS\u00a0– \u00a0n\u00edvel sonoro ou n\u00edvel de intensidade ou intensidade auditiva\u00a0O n\u00edvel sonoro NS \u00e9 medido em<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>decibel (dB).<\/b><\/span><\/span><\/p>\n

32. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— diminui a medida que voc\u00ea se afasta da fonte.<\/b><\/span><\/span><\/p>\n

64. Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>— veja tabela abaixo.<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

Soma (02 + 64)= 66<\/b><\/span><\/span><\/p>\n

09- 01. Correta.<\/b><\/span><\/p>\n

02- Correta<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>As ondas s\u00e3o fortemente difratadas\u00a0 quando o<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>comprimento de onda<\/b><\/span><\/span>\u00a0\u00a0tem<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>aproximadamente o mesmo tamanho\u00a0 da abertura \u00a0da fenda<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>(figura 2)<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>ou do tamanho do obst\u00e1culo<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>(figura 1).<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

Figura 1\u00a0<\/b><\/span><\/span><\/p>\n

\"\"<\/p>\n

figura\u00a0 2<\/b><\/span><\/span><\/p>\n

Observe na figura da esquerda que a difra\u00e7\u00e3o \u00e9 menos acentuada que na direita.<\/b><\/span><\/span><\/p>\n

04. Correta<\/b><\/span>. \u00a0<\/b><\/span><\/span><\/p>\n

08. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u03bb=h\/mV<\/b><\/span><\/span>=6,63.10<\/b><\/span><\/span>-34<\/b><\/span><\/sup><\/span>\/9,1.10<\/b><\/span><\/span>-31<\/b><\/span><\/sup><\/span>.3.10<\/b><\/span><\/span>6<\/b><\/span><\/sup><\/span>=6,63.10<\/b><\/span><\/span>-34<\/b><\/span><\/sup><\/span>\/27,3.10<\/b><\/span><\/span>-25<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u03bb=2,4.10<\/b><\/span>-10<\/b><\/span><\/sup>m.<\/b><\/span><\/p>\n

16. Falsa<\/b><\/span>.<\/b><\/span><\/span><\/p>\n

32. Falsa<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>—<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Foi<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Thomas Young<\/b><\/span>\u00a0<\/b><\/span><\/span><\/span>quem realizou o experimento da dupla fenda.<\/b><\/span><\/span><\/p>\n

Soma (01 + 02 + 04)=07<\/b><\/span><\/span><\/p>\n

<\/h2>\n

Voltar para exerc\u00edcios.<\/span><\/a><\/h2>\n","protected":false},"excerpt":{"rendered":"

RESOLU\u00c7\u00d5ES 01- 01. Falsa\u00a0— a\u00a0energia cin\u00e9tica\u00a0(Ec=mV2\/2) depende da\u00a0velocidade\u00a0do dardo — no ponto\u00a0mais alto\u00a0da trajet\u00f3ria avelocidade vertical \u00e9 nula\u00a0mas existe\u00a0a velocidade horizontal que \u00e9 constante durante todo o movimento. 02. Correta\u00a0— a\u00a0velocidade de lan\u00e7amento \u00e9\u00a0V=25m\/s\u00a0e, nesse instante\u00a0Ec=mV2\/2=0,8.625\/2=250J, que\u00a0independe\u00a0do \u00e2ngulo de lan\u00e7amento. 04. Falsa —\u00a0na\u00a0altura m\u00e1xima\u00a0Vy=o\u00a0—\u00a0voy=Vo.sen30o=25.0,5 —\u00a0Voy=12,5m\/s\u00a0—\u00a0Vy2\u00a0= Voy2\u00a0\u2013 2.g.h\u00a0— 02= 12,52\u00a0\u2013 2.10.h —\u00a0hmax=156.25=7,81m. 08. Falsa\u00a0— n\u00e3o depende da\u00a0massa\u00a0do dardo. 16. Correta\u00a0— o<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":686,"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-688","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/688","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=688"}],"version-history":[{"count":1,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/688\/revisions"}],"predecessor-version":[{"id":689,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/688\/revisions\/689"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/686"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=688"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}