{"id":2432,"date":"2016-09-11T00:37:24","date_gmt":"2016-09-11T00:37:24","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=2432"},"modified":"2024-08-23T15:05:42","modified_gmt":"2024-08-23T15:05:42","slug":"resolucao-comentada-dos-exercicios-de-vestibulares-sobre-equacao-da-onda","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/ondulatoria\/ondas\/equacao-da-onda-equacao-fundamental-da-ondulatoria\/resolucao-comentada-dos-exercicios-de-vestibulares-sobre-equacao-da-onda\/","title":{"rendered":"Equa\u00e7\u00e3o da Onda – Resolu\u00e7\u00e3o"},"content":{"rendered":"

Resolu\u00e7\u00e3o comentada dos exerc\u00edcios de vestibulares sobre <\/b><\/span><\/span><\/span><\/p>\n

Equa\u00e7\u00e3o da Onda (Equa\u00e7\u00e3o fundamental da Ondulat\u00f3ria)<\/b><\/span><\/span><\/span><\/p>\n

01-<\/b><\/span><\/span><\/span> <\/b>B\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

02-<\/b><\/span><\/span><\/span> <\/b><\/p>\n

Falsa \u2013 T=1\/25\u00a0 —\u00a0 T=0,04s<\/b><\/span><\/span><\/span><\/p>\n

Falsa \u2013 A=3m<\/b><\/span><\/span><\/span><\/p>\n

Verdadeira \u2013 V=l.f\u00a0 —\u00a0 V=0,2.25\u00a0 —\u00a0 V=5m\/s<\/b><\/span><\/span><\/span><\/p>\n

Verdadeira<\/b><\/span><\/span><\/span><\/p>\n

Falsa —\u00a0l=20cm=0,2m<\/b><\/span><\/span><\/span><\/p>\n

03- <\/b><\/span><\/span><\/span>E<\/b><\/span><\/span><\/span><\/p>\n

04-<\/b><\/span><\/span><\/span><\/span><\/p>\n

F=6\/1,5=<\/b><\/span><\/span><\/span><\/span>4Hz\u00a0<\/b><\/span><\/span><\/span><\/span>\u00a0—\u00a0 T=1\/f=1\/4=<\/b><\/span><\/span><\/span><\/span>0,25s<\/b><\/span><\/span><\/span><\/span><\/p>\n

05-<\/b><\/span><\/span><\/span><\/span><\/p>\n

a)\u00a0<\/b><\/span><\/span><\/span><\/span>40cm<\/b><\/span><\/span><\/span><\/span><\/p>\n

b)V=\"\"S\/\"\"t\u00a0 —\u00a0 V=20\/0,1\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>V=200cm\/s=2m\/s\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>V=\u03bb.f\u00a0 —\u00a0 2=0,4.f\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>f=5Hz<\/b><\/span><\/span><\/span><\/span><\/p>\n

06-<\/b><\/span><\/span><\/span><\/span>\u00a0\"\"<\/b><\/span><\/span><\/span><\/span>S=0,2m\u00a0 —\u00a0\u00a0\"\"t=0,008s\u00a0 —\u00a0 V=\"\"S\/\"\"t\u00a0 —\u00a0 V=2.10<\/b><\/span><\/span><\/span><\/span>-1<\/b><\/span><\/span><\/span><\/sup><\/span>\/8.10<\/b><\/span><\/span><\/span><\/span>-3<\/b><\/span><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0 V=0,25.10<\/b><\/span><\/span><\/span><\/span>2<\/b><\/span><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>V=25m\/s<\/b><\/span><\/span><\/span><\/span><\/p>\n

07-<\/b><\/span><\/span><\/span><\/span> <\/b>a) f=40Hz\u00a0 —\u00a0 T=1\/f\u00a0 —\u00a0 T=1\/40\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>T=0,025=2,5.10<\/b><\/span><\/span><\/span><\/span>-2<\/b><\/span><\/span><\/span><\/sup><\/span>s<\/b><\/span><\/span><\/span><\/span><\/p>\n

b) V=\u03bb.f\u00a0 —\u00a0 V=15.40\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>V=600cm\/s=6m\/s<\/b><\/span><\/span><\/span><\/span><\/p>\n

08-<\/b><\/span><\/span><\/span> \u00a0<\/b><\/span><\/span><\/span>a) V=\u03bb.f\u00a0 —\u00a0 V=12.30\u00a0 —\u00a0 V=360m\/s (constante-mesmo meio)<\/b><\/span><\/span><\/span><\/p>\n

O menor\u00a0\u03bb\u00a0ocorre quando f=60Hz (vide gr\u00e1fico)\u00a0 —\u00a0 360=\u03bb.60\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span>m\u00ednimo<\/b><\/span><\/span><\/sub><\/span>=6m<\/b><\/span><\/span><\/span><\/p>\n

b) Quando\u00a0\u03bb=12m, f=30Hz\u00a0 —\u00a0 T=1\/f\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>T=1\/30 s<\/b><\/span><\/span><\/span><\/p>\n

09-<\/b><\/span><\/span><\/span><\/span> <\/b>V=\"\"F\/\"\"\u00a0 —\u00a0 V=\"\"64\/0,01)\u00a0 —\u00a0 V=\"\"6.400\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>V= 80 m\/s<\/b><\/span><\/span><\/span><\/span><\/p>\n

10-<\/b><\/span><\/span><\/span><\/span>\u00a0\"\"<\/b><\/span><\/span><\/span><\/span>=m\/L\u00a0 —\u00a0\u00a0\"\"=0,01\/2\u00a0 —\u00a0\u00a0\u00b5=0,005kg\/m\u00a0 —\u00a0 V=\"\"200\/0,005\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>V=200m\/s<\/b><\/span><\/span><\/span><\/span><\/p>\n

11-<\/b><\/span><\/span><\/span><\/span> <\/b>V=\"\"F\/\u00b5\u00a0 —\u00a0 40=\"\"24\/\u00b5\u00a0 —\u00a0 (40)<\/b><\/span><\/span><\/span><\/span>2<\/b><\/span><\/span><\/span><\/sup><\/span>\u00a0= (\"\"24\/\u00b5)<\/b><\/span><\/span><\/span><\/span>2<\/b><\/span><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0 1600 = 24\/\u00b5\u00a0 —\u00a0\u00a0\u00b5\u00a0= 0,015kg\/m<\/b><\/span><\/span><\/span><\/span><\/p>\n

\u00b5 =m\/L\u00a0 —\u00a0 0,015 = m\/2\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>m=0,03kg=3,0.10<\/b><\/span><\/span><\/span><\/span>-2<\/b><\/span><\/span><\/span><\/sup><\/span>kg\u00a0<\/b><\/span><\/span><\/span><\/span><\/p>\n

12-<\/b><\/span><\/span><\/span> \u00a0<\/b><\/span><\/span><\/span>\u00b5 =10<\/b><\/span><\/span><\/span>-2<\/b><\/span><\/span><\/sup><\/span>kg\/m\u00a0 — F=16N\u00a0 —\u00a0\u00a0\u03bb=4m\u00a0 —\u00a0 V=\"\"F\/\u00b5\u00a0 —\u00a0 V=\"\"16\/10<\/b><\/span><\/span><\/span>-2<\/b><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0 V=4.10\u00a0 —\u00a0 V=40m\/s<\/b><\/span><\/span><\/span><\/p>\n

V=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>.f\u00a0\u00a0\u00a0 —\u00a0\u00a0 40=4f\u00a0 —\u00a0<\/b><\/span><\/span><\/span>\u00a0f=10Hz<\/b><\/span><\/span><\/span><\/p>\n

13-<\/b><\/span><\/span><\/span> \u00a0<\/b><\/span><\/span><\/span>P=mg\u00a0 — 52,9=m.10\u00a0 —\u00a0 m=5,29kg\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0m=m\/L\u00a0 —\u00a0\u00a0m=5,29\/0,5\u00a0 —\u00a0\u00a0m=10,58kg\/m<\/b><\/span><\/span><\/span><\/p>\n

V=\"\"F=P\/\u00a0m\u00a0 —\u00a0 V=\"\"52,9\/10,58\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>V=\"\"5 m\/s<\/b><\/span><\/span><\/span><\/span><\/p>\n

14-<\/b><\/span><\/span><\/span><\/span> <\/b>V=<\/b><\/span><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span>.f\u00a0 —\u00a0 340=3,4.10<\/b><\/span><\/span><\/span><\/span>-3<\/b><\/span><\/span><\/span><\/sup><\/span>.f\u00a0\u00a0 —\u00a0<\/b><\/span><\/span><\/span><\/span>\u00a0f=10<\/b><\/span><\/span><\/span><\/span>5<\/b><\/span><\/span><\/span><\/sup><\/span>Hz<\/b><\/span><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span><\/span><\/p>\n

15- <\/b><\/span><\/span><\/span>R-<\/b><\/span><\/span>A<\/b><\/span><\/span><\/span><\/p>\n

Da figura\u00a0 —\u00a0\u00a0\u03bb=20m\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Do gr\u00e1fico\u00a0 —\u00a0 T=10s\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 f=1\/T\u00a0 —\u00a0 f=1\/10Hz<\/b><\/span><\/span><\/span><\/p>\n

V=\u03bb.f\u00a0\u00a0\u00a0 —\u00a0\u00a0 V=20.1\/10\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>V=2,0m\/s<\/b><\/span><\/span><\/span><\/p>\n

16-<\/b><\/span><\/span><\/span> <\/b>R: C\u00a0 —\u00a0 Como a freq\u00fc\u00eancia diminui, o per\u00edodo que \u00e9 seu inverso, aumenta.<\/b><\/span><\/span><\/span><\/p>\n

17-<\/b><\/span><\/span><\/span> <\/b>R: C\u00a0 —\u00a0 No v\u00e1cuo todas essas radia\u00e7\u00f5es eletromagn\u00e9ticas se propagam com velocidade constante de 3,0.10<\/b><\/span><\/span><\/span>8<\/b><\/span><\/span><\/sup><\/span>m\/s e V=\u03bb.f<\/b><\/span><\/span><\/span><\/p>\n

18-<\/b><\/span><\/span><\/span><\/span>\u00a0 <\/b><\/span><\/span><\/span><\/span>V=\u03bb.f \u00a0—\u00a0 V=2.6\u00a0 —\u00a0 V=12cm\/s\u00a0 —\u00a0 V=DS\/Dt\u00a0 —\u00a0 12=60\/Dt\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>Dt=5s<\/b><\/span><\/span><\/span><\/span><\/p>\n

19-<\/b><\/span><\/span><\/span><\/span> \u00a0<\/b><\/span><\/span><\/span><\/span>C<\/b><\/span><\/span><\/span><\/span><\/p>\n

\u03bb=150km\u00a0 —\u00a0 V=750km\/h\u00a0 —\u00a0 V=\u03bb.f\u00a0 —\u00a0 750=150f\u00a0 —\u00a0 f=5Hz\u00a0 —\u00a0 T=1\/f\u00a0 —\u00a0 T=1\/5h\u00a0 —\u00a0 T=1\/5.60\u00a0 — T=12min<\/b><\/span><\/span><\/span><\/span><\/p>\n

20-<\/b><\/span><\/span><\/span><\/p>\n

a) Trata-se de uma onda mista, pois oscila na horizontal e na vertical e estas oscila\u00e7\u00f5es numa onda mista ocorrem no mesmo tempo nestas duas dire\u00e7\u00f5es.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Observe na figura acima, que o intervalo de tempo de 6s corresponde a tr\u00eas quartos do per\u00edodo T, ou seja, T=8s.<\/b><\/span><\/span><\/span><\/p>\n

b) f=1\/T\u00a0 —\u00a0 f=1\/8Hz\u00a0 —\u00a0 V=\u03bb.f\u00a0 —\u00a0 1,5=\u03bb.1\/8 \u00a0—\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb=12m<\/b><\/span><\/span><\/span><\/p>\n

c)<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

21-<\/b><\/span><\/span><\/span><\/p>\n

a) O N<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0\u00e9 puro quando a fra\u00e7\u00e3o molar \u00e9 zero, ou seja, quando V=350m\/s.\u00a0\u00a0 V=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>.f\u00a0 —\u00a0 350=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>.800.000\u00a0 —\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>=4,3.10<\/b><\/span><\/span><\/span>-4<\/b><\/span><\/span><\/sup><\/span>m<\/b><\/span><\/span><\/span><\/p>\n

b)\u00a0 A 60% – V=325m\/s\u00a0 —\u00a0 V=\"\"S\/\"\"t\u00a0 —\u00a0 325=0,1\/\"\"t\u00a0 —\u00a0\u00a0\"\"t=0,00307\u00a0 —\u00a0\u00a0\"\"<\/b><\/span><\/span><\/span>t=3,1.10<\/b><\/span><\/span><\/span>-3<\/b><\/span><\/span><\/sup><\/span>\u00a0s<\/b><\/span><\/span><\/span><\/p>\n

22-<\/b><\/span><\/span><\/span><\/p>\n

a) V=\u03bb.f\u00a0 —\u00a0 3.108=\u03bb.1.500.10<\/b><\/span><\/span><\/span>6<\/b><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb=2,0.10<\/b><\/span><\/span><\/span>-1<\/b><\/span><\/span><\/sup><\/span>m\u00a0\u00a0\u00a0\u00a0 — porcentagem (fra\u00e7\u00e3o) nula<\/b><\/span><\/span><\/span><\/p>\n

b)\u00a0 V=\"\"S\/\"\"t\u00a0 —\u00a0 3.10<\/b><\/span><\/span><\/span><\/span>8<\/b><\/span><\/span><\/span><\/sup><\/span>=100\/\"\"t\u00a0 —\u00a0\u00a0\"\"<\/b><\/span><\/span><\/span><\/span>t = 3,3.10<\/b><\/span><\/span><\/span><\/span>-7<\/b><\/span><\/span><\/span><\/sup><\/span>\u00a0s<\/b><\/span><\/span><\/span><\/span><\/p>\n

23-<\/b><\/span><\/span><\/span><\/span><\/p>\n

a) V=\u03bb.f\u00a0 —\u00a0\u00a0 200=150.10<\/b><\/span><\/span><\/span><\/span>3<\/b><\/span><\/span><\/span><\/sup><\/span>.f\u00a0 —\u00a0 f=2\/15.10<\/b><\/span><\/span><\/span><\/span>-2<\/b><\/span><\/span><\/span><\/sup><\/span>Hz\u00a0 —\u00a0 T=1f\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>T=7,5.10<\/b><\/span><\/span><\/span><\/span>2<\/b><\/span><\/span><\/span><\/sup><\/span>s ou T=750s<\/b><\/span><\/span><\/span><\/span><\/p>\n

b) V=\"\"g.h\u00a0 —\u00a0 V=\"\"10.6,4\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span>V=8m\/s<\/b><\/span><\/span><\/span><\/span><\/p>\n

c) Como V.A<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0\u00e9 constante\u00a0 — V<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>.A<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0na regi\u00e3o de forma\u00e7\u00e3o \u00e9 igual a V<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>.A<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0na profundidade de 6,4m<\/b><\/span><\/span><\/span><\/p>\n

200.1=8.A<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>A=5m<\/b><\/span><\/span><\/span><\/p>\n

24-<\/b><\/span><\/span><\/span><\/p>\n

a) De acordo com o gr\u00e1fico a velocidade m\u00ednima ocorre quando V=1505m\/s, na profundidade de 75m<\/b><\/span><\/span><\/span><\/p>\n

b)<\/b><\/span><\/span><\/span><\/p>\n

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

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

25-<\/b><\/span><\/span><\/span> <\/b>Observe que, em cada 0,5s, cada crista ou cada vale ou cada ponto da onda percorre 1m<\/b><\/span><\/span><\/span><\/p>\n

V=S\/t\u00a0 —\u00a0 V=1\/05\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>V=2m\/s<\/b><\/span><\/span><\/span><\/p>\n

26-<\/b><\/span><\/span><\/span><\/p>\n

a) f =\u03bbB\u00a0 —\u00a0 63.10<\/b><\/span><\/span><\/span>6<\/b><\/span><\/span><\/sup><\/span>=42.10<\/b><\/span><\/span><\/span>6<\/b><\/span><\/span><\/sup><\/span>.B\u00a0 —\u00a0 B=1,5T\u00a0\u00a0\u00a0\u00a0\u00a0 Pelo gr\u00e1fico, quando B=1,5T \u2013\u00a0<\/b><\/span><\/span><\/span>x=1.0m<\/b><\/span><\/span><\/span><\/p>\n

b) V=\u03bbf\u00a0 — 3.10<\/b><\/span><\/span><\/span>8<\/b><\/span><\/span><\/sup><\/span>=\u03bb.63.10<\/b><\/span><\/span><\/span>6<\/b><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0\u00a0\u03bb=0,0476.10<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb=4,76m<\/b><\/span><\/span><\/span><\/p>\n

27-<\/b><\/span><\/span><\/span> \u00a0<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/span><\/p>\n

Mais rasa\u00a0 —\u00a0 V<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=\"\"2,5.10\u00a0 —\u00a0 V<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=5m\/s\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Mais profunda\u00a0 —\u00a0 V<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=\"\"10.10\u00a0 —\u00a0 V<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=10m\/s<\/b><\/span><\/span><\/span><\/p>\n

Como f \u00e9 a mesma\u00a0 — V<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=\u03bb<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>.f\u00a0 —\u00a0 5=\u03bb<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>.f\u00a0 — f=5\/\u03bb<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/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 V<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>.f\u00a0 —\u00a0 10=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>.f\u00a0 —\u00a0 f=10\/<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span><\/p>\n

5\/<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=10\/<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>2\u00a0<\/b><\/span><\/span><\/sub><\/span>\u00a0—\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=2\/<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span><\/p>\n

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

28-<\/b><\/span><\/span><\/span><\/p>\n

a) No gr\u00e1fico da figura 1\u00a0 —\u00a0 T=5s\u00a0 —\u00a0 f=1\/T\u00a0 —\u00a0 f=1\/5\u00a0 —\u00a0<\/b><\/span><\/span><\/span>f=0,2Hz<\/b><\/span><\/span><\/span><\/p>\n

b) No gr\u00e1fico da figura 2\u00a0\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb=25m<\/b><\/span><\/span><\/span><\/p>\n

c) V=\u03bb.f\u00a0 —\u00a0 V=25.0,2\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>V=5m\/s<\/b><\/span><\/span><\/span><\/p>\n

d)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

29-<\/b><\/span><\/span><\/span>a) V=\u03bb.f\u00a0 —\u00a0 3=5f\u00a0 —\u00a0 f=3\/5\u00a0 —\u00a0<\/b><\/span><\/span><\/span>f=0,6Hz<\/b><\/span><\/span><\/span><\/p>\n

b) N\u00e3o se alteram, pois a amplitude A n\u00e3o est\u00e1 relacionada com V, f el, mas apenas com a quantidade de energia transportada pela onda. Quanto maior a energia, maior a amplitude e vice-versa<\/b><\/span><\/span><\/span><\/p>\n

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

30-<\/b><\/span><\/span><\/span> <\/b>a) V=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>.f\u00a0 —\u00a0 2=10.f\u00a0 —\u00a0 f=0,2Hz\u00a0 —\u00a0 T=1\/f\u00a0 —\u00a0 T=1\/0,2\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>T=5s<\/b><\/span><\/span><\/span><\/p>\n

b) Como se movem em sentido contr\u00e1rio a velocidade relativa entre o barco e a onda \u00e9 de V=2 + 8\u00a0 —\u00a0 V=10m\/s<\/b><\/span><\/span><\/span><\/p>\n

\u00a0\u00a0\u00a0\u00a0 V=\"\"S\/\"\"t\u00a0 —\u00a0 10=10\/\"\"t\u00a0 —\u00a0\u00a0\"\"<\/b><\/span><\/span><\/span>t=1s<\/b><\/span><\/span><\/span><\/p>\n

31-<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>\u00a0= 12 cm = 0,12 m\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>c\u00a0<\/b><\/span><\/span><\/span>= 300.000 km\/s = 3<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/sub><\/span>10<\/b><\/span><\/span><\/span>8<\/b><\/span><\/span><\/sup><\/span>\u00a0m\/s\u00a0 —\u00a0 V=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>f\u00a0 —\u00a0 f=V\/<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>=3.10<\/b><\/span><\/span><\/span>8<\/b><\/span><\/span><\/sup><\/span>\/0,12\u00a0 —\u00a0 f=2,5.10<\/b><\/span><\/span><\/span>9<\/b><\/span><\/span><\/sup><\/span>\u00a0Hz\u00a0 —\u00a0 f=2,5MHz\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>R- D<\/b><\/span><\/span><\/span><\/p>\n

32-<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>v =\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>f \u00a0— \u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>=V\/f=10<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sup><\/span>\/10<\/b><\/span><\/span><\/span>11<\/b><\/span><\/span><\/sup><\/span>=10<\/b><\/span><\/span><\/span>-7<\/b><\/span><\/span><\/sup><\/span>m\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>=100.10<\/b><\/span><\/span><\/span>-9<\/b><\/span><\/span><\/sup><\/span>m=100nm\u00a0 —\u00a0 sendo, pelo enunciado, d=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>\u00a0 —\u00a0 d=100nm\u00a0 —\u00a0<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span><\/p>\n

R- C<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/sub><\/span><\/p>\n

33-<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Observe na figura que entre as duas \u00e1rvores voc\u00ea observa 4 comprimentos de onda (<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>)\u00a0 —\u00a0 4<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>=120\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>=30m\u00a0 —\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

V=\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>f\u00a0 — V=30.0,5\u00a0 —\u00a0 V=15m\/s\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>R- E<\/b><\/span><\/span><\/span><\/p>\n

34-<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>A velocidade de propaga\u00e7\u00e3o \u00e9 dada pela express\u00e3o\u00a0 —\u00a0\"\"\u00a0\u00a0—\u00a0\u00a0\"\"<\/b><\/span><\/span><\/span>\u00a0\u00a0<\/b><\/span><\/span><\/sub><\/span>—\u00a0 movimento uniforme\u00a0 —\u00a0 V=\u2206S\/\u2206t\u00a0 —\u00a0 25=10\/\u2206t\u00a0 —\u00a0 \u2206t=0,4s<\/b><\/span><\/span><\/sub><\/span>\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/sub><\/span>R- B<\/b><\/span><\/span><\/span><\/p>\n

35-<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Do painel\u00a0 —\u00a0\u00a0 menor frequ\u00eancia – f<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0= 88 MHz\u00a0 —\u00a0\u00a0 maior frequ\u00eancia – f<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= 108 MHz\u00a0 —\u00a0 equa\u00e7\u00e3o fundamental da ondulat\u00f3ria, V =\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/sub><\/span>f\u00a0 —\u00a0 nessa equa\u00e7\u00e3o voc\u00ea conclui que, num mesmo meio (mesma velocidade V), o maior comprimento deondacorresponde\u00e0 menor frequ\u00eancia e vice-versa\u00a0 —\u00a0 V =\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>1\u00a0<\/b><\/span><\/span><\/sub><\/span>f<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0e V =\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>2\u00a0<\/b><\/span><\/span><\/sub><\/span>f<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0 —\u00a0 igualando-as\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>1\u00a0<\/b><\/span><\/span><\/sub><\/span>f<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0=\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>2\u00a0<\/b><\/span><\/span><\/sub><\/span>f<\/b><\/span><\/span><\/span>2\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/sub><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>1.<\/b><\/span><\/span><\/sub><\/span>88 =\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>2.<\/b><\/span><\/span><\/sub><\/span>108<\/b><\/span><\/span><\/span>\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/sub><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>1\/<\/b><\/span><\/span><\/sub><\/span>\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>2 <\/b><\/span><\/span><\/sub><\/span>= 1,23\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>R- E<\/b><\/span><\/span><\/span><\/p>\n

36-<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Observando o gr\u00e1fico voc\u00ea v\u00ea que, o per\u00edodo do batimento desse atleta \u00e9 0,5 s\u00a0 —\u00a0 T=0,5s\u00a0 —\u00a0 f=1\/T=1\/0,5\u00a0 —\u00a0 f=2Hz\u00a0 —\u00a0 portanto, voc\u00ea tem 2 batimentos por segundo ou 2.60=120 batimentos por minuto\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>R- D<\/b><\/span><\/span><\/span><\/p>\n

37-<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Do gr\u00e1fico, voc\u00ea observa que o tempo entre dois picos consecutivos (per\u00edodo) \u00e9 T<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>= 10<\/b><\/span><\/span><\/span>\u201316<\/b><\/span><\/span><\/sup><\/span>\u00a0s\u00a0 —\u00a0 f=1\/T=1\/10<\/b><\/span><\/span><\/span>-16<\/b><\/span><\/span><\/sup><\/span>\u00a0 —\u00a0\u00a0 f=10<\/b><\/span><\/span><\/span>16<\/b><\/span><\/span><\/sup><\/span>Hz\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>R- C<\/b><\/span><\/span><\/span><\/p>\n

38-<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>V = 1.188km\/h = 330 m\/s \u00a0—\u00a0\u00a0<\/b><\/span><\/span><\/span>f<\/b><\/span><\/span><\/span>\u00a0= 2.640 Hz\u00a0 —\u00a0 V=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>f\u00a0\u00a0\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>=V\/f=330\/2.640\u00a0 —<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>=0,125m<\/b><\/span><\/span><\/span><\/p>\n

39-<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>Observe na figura que\u00a0 —\u00a0 equa\u00e7\u00e3o da onda\u00a0 —\u00a0 V=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>f\u00a0 —\u00a0 10=<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>.1\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>=10m\u00a0 —\u00a0 comprimento da ponte\u00a0 —\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

L=3<\/b><\/span><\/span><\/span>\u03bb<\/b><\/span><\/span><\/span><\/span>\/2\u00a0 —\u00a0 L=3.10\/2\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>L=15m<\/b><\/span><\/span><\/span><\/p>\n

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

40-<\/b><\/span><\/span><\/span><\/p>\n

\u00a0<\/span>\u00a0<\/span>Veja na figura abaixo que um comprimento de onda \u03bb vale\u00a0 —\u00a0 1,5\u03bb\/2=15\u00a0 —\u00a0 \u03bb=15\/1,5=10cm=0,1m\u00a0 —\u00a0 equa\u00e7\u00e3o<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

fundamental da ondulat\u00f3ria\u00a0 —\u00a0 V=\u03bbf=0,1.740\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>V=74m\/s<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

41-<\/b><\/span><\/span><\/span><\/p>\n

\u00a0Observe no gr\u00e1fico fornecido que o per\u00edodo T (tempo que as ondas superficiais na superf\u00edcie da \u00e1gua geradas pela aranha demoram para efetuar uma oscila\u00e7\u00e3o completa) vale T=4ms=4.10<\/b><\/span><\/span><\/span>-3<\/b><\/span><\/span><\/sup><\/span>s\u00a0 —\u00a0 frequ\u00eancia dessas ondas\u00a0 —\u00a0 f=1\/T\u00a0 —<\/b><\/span><\/span><\/span><\/p>\n

f=1\/(4.10<\/b><\/span><\/span><\/span>-3<\/b><\/span><\/span><\/sup><\/span>)\u00a0 —\u00a0 f=0,25.10<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sup><\/span>=250Hz\u00a0 —\u00a0 equa\u00e7\u00e3o fundamental da ondulat\u00f3ria\u00a0 —\u00a0 v=\u03bbf=2.10<\/b><\/span><\/span><\/span>-3<\/b><\/span><\/span><\/sup><\/span>.250\u00a0 —\u00a0 v=500.10<\/b><\/span><\/span><\/span>-3<\/b><\/span><\/span><\/sup><\/span>m\/s\u00a0 —\u00a0 v=0,5m\/s=50cm\/s\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>R- B.<\/b><\/span><\/span><\/span><\/p>\n

42-<\/b><\/span><\/span><\/span> <\/b>A velocidade de uma onda eletromagn\u00e9tica no interior do cabo \u00e9 dada por\u00a0 v = c\/n = . Qual \u00e9 o comprimento de onda de uma onda de frequ\u00eancia\u00a0 f = 400 MHz que se propaga num cabo cujo isolante \u00e9 o polietileno ( K , = 2,25 )?<\/b><\/span><\/span><\/span><\/p>\n

Como a velocidade da luz no v\u00e1cuo (e aproximadamente no ar) \u00e9 constante\u00a0 —\u00a0 v= \u03bb.f =constante\u00a0 —\u00a0 para que \u03bb.f \u00a0seja constante eles devem ser inversamente proporcionais, ou seja, \u00e0 menor frequ\u00eancia f est\u00e1 associada ao maior comprimento \u03bb\u00a0 —\u00a0 a haste que apresenta maior comprimento \u00e9 a \u00faltima da direita que mede L=30cm=0,3m\u00a0 —\u00a0 como, pelo enunciado,\u00a0 L \u2248 \u03bb\/2\u00a0\u00a0 —\u00a0<\/b><\/span><\/span><\/span><\/p>\n

\u03bb =2.L=2.0,3=0,6m\u00a0 —\u00a0 v= \u03bb.f\u00a0 —\u00a0 3.10<\/b><\/span><\/span><\/span>8<\/b><\/span><\/span><\/sup><\/span>= 0,6.f\u00a0 —\u00a0<\/b><\/span><\/span><\/span>\u00a0f=5,0.10<\/b><\/span><\/span><\/span>8\u00a0<\/b><\/span><\/span><\/sup><\/span>Hz<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

43-<\/b><\/span><\/span><\/span><\/p>\n

–<\/b><\/span><\/span><\/span>\u00a0I. Falsa\u00a0 —\u00a0 como as cordas s\u00e3o id\u00eanticas, elas possuem a mesma densidade linear \u03bc (massa por unidade de comprimento), mas como as tra\u00e7\u00f5es T s\u00e3o diferentes, pela express\u00e3o V=\u221a(T\/\u03bc) as velocidades tamb\u00e9m devem ser diferentes.<\/b><\/span><\/span><\/span><\/p>\n

II. Correta\u00a0 —\u00a0 observe no gr\u00e1fico que \u03b3<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>= \u03b3<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=4m.<\/b><\/span><\/span><\/span><\/p>\n

III. Falsa\u00a0 —\u00a0 equa\u00e7\u00e3o fundamental da ondulat\u00f3ria\u00a0 —\u00a0 V= \u03b3.<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/sub><\/span>f\u00a0 —\u00a0 se as velocidades s\u00e3o diferentes e \u03b3<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/sub><\/span>\u00e9 o mesmo, as freq\u00fc\u00eancias f devem ser diferentes.<\/b><\/span><\/span><\/span><\/p>\n

R- B<\/b><\/span><\/span><\/span><\/p>\n

44-<\/b><\/span><\/span><\/span><\/p>\n

3 \u03bb\/2=0,51\u00a0 —\u00a0 3\u03bb=1,02\u00a0 —\u00a0 \u03bb=0,34m\u00a0 —\u00a0 equa\u00e7\u00e3o fundamental da ondulat\u00f3ria\u00a0 —\u00a0 V= \u03bbf\u00a0 —\u00a0 340=0,34.f\u00a0 —\u00a0 f=1000Hz\u00a0 —\u00a0 se a dist\u00e2ncia da pessoa ao obst\u00e1culo \u00e9 d, o som vai e volta percorrendo 2d, com V=340m\/s em \u2206t=2,0s\u00a0 —\u00a0 V=2d\/\u2206t\u00a0 —\u00a0 340=2d\/2,0\u00a0 —\u00a0 d=d=340m\u00a0 —\u00a0\u00a0<\/b><\/span><\/span><\/span>R- B<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

 <\/p>\n

 <\/p>\n

Voltar para os exerc\u00edcios<\/span><\/a><\/h3>\n","protected":false},"excerpt":{"rendered":"

Resolu\u00e7\u00e3o comentada dos exerc\u00edcios de vestibulares sobre Equa\u00e7\u00e3o da Onda (Equa\u00e7\u00e3o fundamental da Ondulat\u00f3ria) 01- B\u00a0\u00a0\u00a0\u00a0 02- Falsa \u2013 T=1\/25\u00a0 —\u00a0 T=0,04s Falsa \u2013 A=3m Verdadeira \u2013 V=l.f\u00a0 —\u00a0 V=0,2.25\u00a0 —\u00a0 V=5m\/s Verdadeira Falsa —\u00a0l=20cm=0,2m 03- E 04- F=6\/1,5=4Hz\u00a0\u00a0—\u00a0 T=1\/f=1\/4=0,25s 05- a)\u00a040cm b)V=S\/t\u00a0 —\u00a0 V=20\/0,1\u00a0 —\u00a0\u00a0V=200cm\/s=2m\/s\u00a0 —\u00a0\u00a0V=\u03bb.f\u00a0 —\u00a0 2=0,4.f\u00a0 —\u00a0\u00a0f=5Hz 06-\u00a0S=0,2m\u00a0 —\u00a0\u00a0t=0,008s\u00a0 —\u00a0 V=S\/t\u00a0 —\u00a0 V=2.10-1\/8.10-3\u00a0 —\u00a0 V=0,25.102\u00a0 —\u00a0\u00a0V=25m\/s 07-<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2428,"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-2432","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2432","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=2432"}],"version-history":[{"count":3,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2432\/revisions"}],"predecessor-version":[{"id":10915,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2432\/revisions\/10915"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/2428"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=2432"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}