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Complex waveform

  1. Mar 23, 2014 #1
    Having some trouble with this question,

    A complex wave is described by equation, y=100 sin ωt+30 sin(3ωt-∏/2)
    A) on the same axis sketch and label,
    1)one cycle of the fundamental waveform
    2)the third harmonic
    3) the complex waveform(y)

    ω=2∏f
    T=2∏/ω

    Not sure where to start.
    To sketch graph I need to find time, to get time I need frequency. Not sure how to find frequency from 100 sin ωt
    as
    Do I just treat ω as 2∏?
     
    Last edited: Mar 23, 2014
  2. jcsd
  3. Mar 23, 2014 #2

    BvU

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    No, you treat ##\omega\, t## as the x coordinate.
     
  4. Mar 23, 2014 #3
    Ok so I have ωt, ωt/2, ωt/3 along my x axis for my time coordinates ?
     
    Last edited: Mar 23, 2014
  5. Mar 23, 2014 #4

    BvU

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    No, just ##\omega \, t##
     
  6. Mar 23, 2014 #5

    BvU

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    If you still feel uncomfortable, choose ##\omega = 1##, make the y, t plot and then rename the t axis to ##\omega t## axis !
     
  7. Mar 23, 2014 #6
    Where i'm getting confused is i'm used to solving the likes of 100 sin (100 ∏ t)

    from there you get time=20ms, so you can plot the time axis up to 20ms.

    I don't understand how to plot ωt
     
  8. Mar 24, 2014 #7

    BvU

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    Perhaps I confused you earlier on, sorry. There is no solving involved, just plotting. One period in A1 -- so from ##100 \, \omega\, t=0 ## to ##100\, \omega\, t=2\pi ##
     

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  9. Mar 24, 2014 #8
    I understand now cheers.
     
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