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Question about a few things

  1. Oct 25, 2005 #1
    What is it that makes a window break when a baseball hits it? Is it Kinetic energy, Momentum, or Pressure?

    Also, how does that relate to and differ from force? Not the force that causes a change in acceleration, but deforms an object. When an object is being twisted,
    the Stiffness and Strength of an object have to be overcome.

    How is using kinetic energy, momentum or pressure to break something relate to and differ from using a force to deform an object?
  2. jcsd
  3. Oct 25, 2005 #2


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    Staff: Mentor

    Kinetic energy being absorbed in the breaking of chemical bonds (electrical potential energy). Have a look at the http://www2.umist.ac.uk/material/research/intmic/features/charpy/notes.htm". Glass is brittle, and because of that it actually takes relatively little energy to break it - even though glass has such a high tensile strength, bridges are occasionally built out of it.
    Last edited by a moderator: Apr 21, 2017
  4. Oct 26, 2005 #3


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    Gold Member

    Glass is probably the most brittle liquid on the planet. In addition to mechanical impact of physical objects, it's also very susceptible to sonic vibrations. (Okay, that wasn't helpful to the thread, but I felt obliged to point it out.):rolleyes:
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