1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Question about vibration

  1. Jan 5, 2008 #1
    If two metal objects hit, do the objects have to vibrate to make a sound? Or can the air itself vibrate with the sound?
  2. jcsd
  3. Jan 5, 2008 #2
    Is there was no air, could you hear the metal objects when they hit?
  4. Jan 5, 2008 #3


    User Avatar
    Science Advisor

    If the objects did not vibrate, what would cause the air to vibrate?
  5. Jan 5, 2008 #4
    I don't know. I thought sound was the result of potential energy being released as kinetic energy (I don't know much about this, bear with my ignorance :| ). So one of the metal objects would have to vibrate for there to be sound?
  6. Jan 5, 2008 #5
    The sound is a wave travelling in the air. When the objects hit they beame sourses of these waves. If there is a medium for these waves to travel (i.e. the air) they will reach at your ears and you will hear the sound.
  7. Jan 5, 2008 #6


    User Avatar

    Staff: Mentor

    The collision itself will push air, creating a sound like thunder or clapping hands. The objects themselves need not vibrate.
  8. Jan 5, 2008 #7
    Oh, okay. That's what I was wondering. Someone told me that one of the objects would have to vibrate for there to be sound, but I figured the air alone would do it. A thought, is this how things like lightning make sound?
  9. Jan 5, 2008 #8


    User Avatar
    Gold Member

    In a way. Thunder (the sound of lightning) is basically the aftermath of an explosion. A lightning bolt is in the millions of degrees, which superheats the surrounding air much as a high explosive such as C-4 would. That overpressure radiates in all directions from the path of the bolt, so the inverse square law applies to the intensity where it's heard.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook