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Thread: Poll about physics & parlor magic

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    Re: Poll about physics & parlor magic

    This isn't a trick, this is basic rigid body dynamics. The ball is free falling. The board is not free falling. Hence, different motions.

    For small angles, the CG of the board (so about halfway up) will fall at nearly free fall speeds (a bit slower because of rotational inertia) and the tip of the board will move at effectively twice that speed. For larger angles, the CG of the board will descend at a noticeably slower rate because only a portion of the gravity force vector (according to the sine of the angle) contributes to rotational acceleration.

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    Re: Poll about physics & parlor magic

    Quote Originally Posted by Hatuey View Post
    ****ing magnets..... how do they work?
    eventually they end up making lots of little magnets ......


    or?

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    Re: Poll about physics & parlor magic

    I know the answer. I suck at physics though, so I did need a bit of help.

     
    The ball starts higher than the cup. They're falling at the same speed. Knowing that, watch it again.

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    Re: Poll about physics & parlor magic

    Quote Originally Posted by Green Balls View Post
    First experiment is obvious, the ball drops straight down and the bucket lines up when the wood post falls.

    2 objects with the same mass will reach the ground at the same time when dropped at the same time. It's obvious a metal pole which already has one end touching the ground will not fall at the same rate of speed since there is resistance. Plain and simple it's a flawed experiment. Drop the whole pole, not one end, and you will see them both reach the ground at the same time.
    Exactly this.

    Not very complicated - though neat to see it in slow mo
    A screaming comes across the sky.
    It has happened before, but there is nothing to compare it to now.
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    Re: Poll about physics & parlor magic

    Quote Originally Posted by Aunt Spiker View Post
    Exactly this.

    Not very complicated - though neat to see it in slow mo
    It is cool to see it in slow motion. I remember a long time ago standing on a bridge with a friend and doing the gravity experiment with various size rocks. They always hit the ground at the same time.
    Scientific fact: If you took all of the veins from your body and laid them end to end, you would die.

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    Re: Poll about physics & parlor magic

    Quote Originally Posted by the_recruit View Post
    This isn't a trick, this is basic rigid body dynamics. The ball is free falling. The board is not free falling. Hence, different motions.

    For small angles, the CG of the board (so about halfway up) will fall at nearly free fall speeds (a bit slower because of rotational inertia) and the tip of the board will move at effectively twice that speed. For larger angles, the CG of the board will descend at a noticeably slower rate because only a portion of the gravity force vector (according to the sine of the angle) contributes to rotational acceleration.
    D00d, do you really believe this stuff
    or are you just putting me on?

    what?

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    Re: Poll about physics & parlor magic

    Quote Originally Posted by Menard_K View Post
    D00d, do you really believe this stuff
    or are you just putting me on?

    what?
    Do I really believe basic physics and rigid body dynamics? Yes. Yes I do.

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    Re: Poll about physics & parlor magic

    Quote Originally Posted by the_recruit View Post
    Do I really believe basic physics and rigid body dynamics? Yes. Yes I do.
    Z0, other physics question for you,
    check out the videos of WTC7 "collapsing" and note that there is a period of 2.25 sec
    where the skyscraper descends at 9.8 m/s^2 ..... what do you make of that ?

    Just curious ......

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    Re: Poll about physics & parlor magic

    Quote Originally Posted by Menard_K View Post
    Z0, other physics question for you,
    check out the videos of WTC7 "collapsing" and note that there is a period of 2.25 sec
    where the skyscraper descends at 9.8 m/s^2 ..... what do you make of that ?

    Just curious ......

    The same thing I make of all the observations and evidence surround the WTC collapse - that the WTC collapsed in accordance with our understanding of physics and mechanics.

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    Re: Poll about physics & parlor magic

    Quote Originally Posted by Menard_K View Post
    Please see

    Faster than gravity - YouTube

    and then give YOUR explanation of what just happened.

    Can U dig it?
    I solved that problem in Math Methods. Geometry, center of mass, torque, and inertia.
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