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Wave Speed Of Standing Wave

  1. Oct 5, 2013 #1
    1. The problem statement, all variables and given/known data

    A wire with an alternating current flowing through it is placed in a magnetic field. This causes the wire to oscillate with a frequency equal to the frequency of the current (you will learn about this when we study electromagnetism). The wire has a length (length is measured from the node at which the wire is tied to the pulley) L = 2.46 m. A mass of 244.0 g is hung on the end of the wire. The frequency of the current is initially set to f = 59.8 Hz. Three loops are observed in the wire at this frequency as shown in the diagram.

    Image attached with this post!

    2. Relevant equations

    (2Lf)2= T/µ.


    3. The attempt at a solution

    µ = T/(2Lf)2 =(0.244*9.8)/(2* 2.46m*59.8 Hz)^2

    This answer was wrong according when inserted!

    Any help finding the velocity or the mass per unit length is kindly appreciated!
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     

    Attached Files:

  2. jcsd
  3. Oct 5, 2013 #2

    mfb

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    Staff: Mentor

    What does the second "2" mean?

    Where did you calculate the wave-length of the oscillation (or, equivalently, where did you use the information that there are three loops)?
     
  4. Oct 5, 2013 #3
    I wasn't too sure how to incorporate that :/ I'm an economics student, doing this physics subject as an elective. I wasn't too sure how you could relate the three looops.
     
  5. Oct 6, 2013 #4

    mfb

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    Staff: Mentor

    Imagine how the loop looks at some specific point in time. A bit like this: "^u^". How many wavelengths are this? And the next question, what is the wavelength then?
     
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