Physics Questions!

posted by .

An interference pattern is set up by two point sources of the same frequency, vibrating in phase with one another. A point on the second nodal line is 50.0 cm from one source and 59 cm from the other. The speed of the waves is 35 cm/s. Calculate the frequency of the sources. I know you do path difference (like Pms-Pms) and then do the universal wave equation, I am confused where it says in phase with one another and the 2nd nodal line

  • Physics Questions! -

    The "first nodal line" is a line along which the path difference is 1/2 wave, a point of destructive interference. In this case, 9 cm is the wavelength, since there would be one extra wavelength in path difference along the second nodal line.

    The frequency is then f = (35 cm/s)/9 cm = 3.9 Hz. Those are very slow waves, by the way. Are you sure you got the units right?

    It does not matter whether the two sources are in phase with one another or not. It affects where the nodes are, but not the separation between the nodes.

    For more background about this, see

  • Physics Questions! -

    mmmh are you sure it is 9 cm? It is destructive interference which means a minimum, therefore PmS1-PmS2= (m+1/2) lambda...I get 9 cm when I don't account for the m + 1/2

  • Physics Questions! -

    You are correct. 9 cm is (3/2) wavelength along a second nodal line. The wavelength is therefore 6 cm.

  • Physics Questions! -

    Thanks for all of your help, I talked to my other friend who had originally posted, and we both appreciate this, thanks!

  • Physics Questions! -

    Sorry about the error. I'm glad you and BobPursley were on the ball. I was thinking of the path length difference between the first and second nodal line.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    Someone has already posted this question, but their's was never answered, so hopefully someone can answer this. Thanks. An interference pattern is set up by two point sources of the same frequency, vibrating in phase with one another. …
  2. Physics - Please Help!

    I really need help on these questions because I have a test tomorrow and don't understand how to do them. 1) A wire of diameter 0.6mm is placed in the path of light coming from a laser. Light diffracts around both sides of the wire; …
  3. Physics

    A vibrating 1000-hertz tuning fork produces sound waves that travel at 340 meters per second in air. Points A and B are some distance from the tuning fork. Point P is 20. meters from the tuning fork. 1. If the waves are in phase at …
  4. physics

    Two point sources, 5.0 cm apart are operating in phase, with a common frequency of 6.0 Hz, in a ripple tank. A metre stick is placed above the water, parallel to the line joining the sources. The first nodal lines (the ones adjacent …
  5. physics

    Two loudspeakers are placed above and below each other and driven by the same source at a frequency of 3.70 102 Hz.An observer is in front of the speakers at point O, at the same distance from each speaker. What minimum vertical distance …
  6. Physics

    Using a swimming pool, two students decide to test the water by setting up an interference pattern at one end of the 50 m pool. They sit 2.0 m apart and create waves by tapping their right foot, in phase with each other, onto the water …
  7. physics

    Fill in blank without a word bank (unit is wave nature of light) 1. As water waves travels through a slit barrier, they bend and spread out. This is known as ______ 2. Two identical waves will interfere destructively, cancelling one …
  8. physics

    Two loudspeakers, A and B, are driven by the same amplifier and emit sinusoidal waves in phase. Speaker B is 12 m to the right of speaker A. The frequency of the waves emitted by each speaker is 686 Hz. Sound velocity is 343 m/s. You …
  9. physics

    Two small loudspeakers emit sound waves of the same amplitude and frequency in phase with each other. The waves produce an interference pattern such that the distance from the right bisector to a point P on the third nodal line is …
  10. physics

    Two point sources produce waves in phase with the same amplitude and wavelength. The sources are a distance d apart. The distance from the right bisector to a point on the second nodal line is x2. The distance between the sources is …

More Similar Questions