Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How do supersonic sources create sonic booms?

  1. Feb 23, 2010 #1
    Why do supersonic waves (when the source is faster than the wave) create sonic booms? I understand that when a source breaks the sound barrier and travels at the speed of its waves, the waves just build up at the front of the source and create a condensed sound of multiply sound waves added together, creating a sonic boom. Yet, when a source is faster than the waves, there is no buildup of waves because a new wave is created in front of the last and goes the same velocity as it so it wouldn't catch up. How do these sources create sonic booms?

    http://physics.info/shock/doppler-shock-4.html [Broken]
    see, they dont overlap
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Feb 23, 2010 #2

    russ_watters

    User Avatar

    Staff: Mentor

    Correct.
    Well....
    Well then what is the dark line on the edge of that wedge-shape they form? It's still a shock wave. All that has happened between that image and this one ( http://physics.info/shock/doppler-shock-3.html [Broken] ) is the angle of the two shock waves has move back/closed from perpendicular to the direction of motion. It isn't like the sound waves for a Mach 1 shock wave stay in one place: they are still propagating out away from the source along the shock wave.
     
    Last edited by a moderator: May 4, 2017
  4. Feb 23, 2010 #3

    Matterwave

    User Avatar
    Science Advisor
    Gold Member

    You must consider not only the "front end" of the cone, but also the sides. For speed faster than the speed of sound, the sides of those circles still add up.

    Remember, sound travels in all directions, not just forward.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: How do supersonic sources create sonic booms?
  1. Sonic boom? (Replies: 1)

Loading...