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arcticf0x Group Title

Potential Energy

  • 2 years ago
  • 2 years ago

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  1. arcticf0x Group Title
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    http://www.youtube.com/watch?v=oAc4TP0MXBk at 47.00

    • 2 years ago
  2. arcticf0x Group Title
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    Why the time difference? Its not angle, friction.. what is it?

    • 2 years ago
  3. arcticf0x Group Title
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    @JamesJ Please share some insight :)

    • 2 years ago
  4. arcticf0x Group Title
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    In that experiment, there is a difference in his prediction time and actual time. Why is that, as WL asks about it.

    • 2 years ago
  5. JamesJ Group Title
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    watching ... one sec

    • 2 years ago
  6. JamesJ Group Title
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    Ok. The difference between the two scenarios is whether or not the object oscillating has angular momentum. In the first case--with the air track--the bob has no intrinsic angular momentum and the situation can be analyzed with just 'translational kinematics'. In the second case, the ball does rotate about an internal axis, it has non-zero moment of inertia and hence it has non-zero angular momentum. Hence there is rotational kinetic energy \[ RKE = \frac{1}{2}I\omega^2 \] and as the ball moves gravity and friction does work on the ball to make it change angular momentum \( \omega \).

    • 2 years ago
  7. arcticf0x Group Title
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    Oh ok, so its the ball's inertia and rotaion! Does that affect his prediction time aswell?

    • 2 years ago
  8. JamesJ Group Title
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    So work is done on the ball to make it change its angular velocity, and that work takes energy away from the other forms of mechanical energy: translational KE and gravitational PE. yes, it most definitely impacts the physics, so the analysis he did on the board was wrong (and of course he knows it; he's making a point).

    • 2 years ago
  9. arcticf0x Group Title
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    Oh ok, so he purposely didnt take that work into account! Cool. But hey, does that roation and initial momentum affect his prediction time?

    • 2 years ago
  10. arcticf0x Group Title
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    Intriguing stuff!

    • 2 years ago
  11. JamesJ Group Title
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    the fact that the object does rotate about its own axis definitely effects the period of oscillation

    • 2 years ago
  12. arcticf0x Group Title
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    Yes indeed! I got the point(s), thanks for your time James!

    • 2 years ago
  13. pastory Group Title
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    p.e math=mgh m=mass g=gravitation h=height

    • 2 years ago
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