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Homework Help: Finding amplitude

  1. Jan 7, 2010 #1
    1. The problem statement, all variables and given/known data
    what is the amplitude of the motion v=-6.54sin(20.1t) (mks units)
    angular frequency=20.1

    2. Relevant equations
    v=wAcoswt


    3. The attempt at a solution
    I think the wavelength is 6.54 since 20.1 is the frequency. v =6.2 m/s. I am missing time.
     
  2. jcsd
  3. Jan 7, 2010 #2
    update: i used T=1/f to find time, divided by four because thats when the displacement will be maximum plugged all this in and got .32, the correct answer I know is .33. I didn't round to the end so I feel like this is luck and not the correct way, am i making this too difficult?
     
  4. Jan 7, 2010 #3

    rock.freak667

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    Homework Helper

    If you know v is in the form v=-ωAsin(ωt) = -6.54sin(20.1t), then shouldn't ωA=6.54 and you know ω=20.1
     
  5. Jan 7, 2010 #4
    You are correct. I thought v=-6.54sin(20.1t) was a form of v=λf and I couldn't figure out where the sin and t came from. Thank you for helping me with a stupid mistake.
     
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