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zoey123

HEEELLLPPPP PLEASEEEE! A sound wave is modeled with the equation y =1/4 cos 2pi/3 theta a. Find the period. Explain your method. b. Find the amplitude. Explain your method

  • one year ago
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  1. Shadowys
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    note that waves can be of general eq, y=r cos wt, where r is the amplitude, w the angular velocity and t is the time parameter.

    • one year ago
  2. VeritasVosLiberabit
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    This looks like physics.

    • one year ago
  3. zoey123
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    well do you know the answer?

    • one year ago
  4. VeritasVosLiberabit
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    Yes but just so you know. This is a physics question not mathematics.

    • one year ago
  5. Shadowys
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    cross reference your eq with the general eq above.

    • one year ago
  6. zoey123
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    ok well can i have the answer?

    • one year ago
  7. Shadowys
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    did you try to do it yourself first?

    • one year ago
  8. zoey123
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    yes and i am beyind confused :/

    • one year ago
  9. Shadowys
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    what did you get? by the way, your equation didnot involve time ......

    • one year ago
  10. zoey123
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    cause thats not what it asked for i just need the period of the graph and what the amplitude would be you do this by using trig and i got the amplitude is 4 and the period is 2 but i dont think that is right

    • one year ago
  11. VeritasVosLiberabit
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    \[\omega = \frac{ 2\pi }{ T }\]

    • one year ago
  12. Shadowys
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    amplitude, A through a mathematical analysis, the amplitude is the highest/lowest point of the curve. \(y =\frac{1}{4}\cos \frac{2\pi}{3}{ \theta}\) \(y' =-\frac{1}{4}(\frac{2\pi}{3})\sin \frac{2\pi}{3}{ \theta}\) let y'=0, \(\sin \frac{2\pi}{3}{ \theta}=0\) \(\theta=0\) y=1/4=A you follow?

    • one year ago
  13. zoey123
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    kinda

    • one year ago
  14. Shadowys
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    yup, now, \(y'=\omega\) the period is the time for two wavecrest, i.e. two amplitude, also aka two y'=0 so you find the w for two successive max points and you'll get it.

    • one year ago
  15. Shadowys
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    on second thought, where is the time parameter=.=

    • one year ago
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