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Ideas for this fun project?

  1. Dec 4, 2013 #1
    Here's the project:
    You have a 60x60x60cm box, and a marble (the material of the marble could be steel, glass, plastic, etc.).
    There are 2 holes in the side(s) of the box that are 20cm vertically apart.
    The marble must start from the lower hole with basically no velocity, and by any non-electrical means shoot out of the upper hole.

    How would you do it?
    What kind of simple machines / devices would you use to propel the marble?

    I am doing this myself, but I am really interested in seeing what some people will come up with!
    Last edited: Dec 4, 2013
  2. jcsd
  3. Dec 4, 2013 #2
    If the marble has enough velocity initially, it can simply be deflected to the top hole.

    If it does not, well, there must be some source of energy in the box to accelerate it.
  4. Dec 6, 2013 #3
    Wow, that sounds interesting! Is this for a class?

    Anyway, how are the holes oriented? Is the second hole directly above the first, or
    is it above the first on the other side of the box. Also, do all mechanisms have to be
    contained within the box? Like voko said, its really just a matter of getting the ball to
    move, upon which you can add a ramp of sorts that leads to the second hole. So you
    could have a lever/hammer thing that knocks it forward.

    But that's boring. Currently I'm imagining some sort of rube Goldberg machine right
    now, so I don't know if you care to hear it. Guess that depends on the purpose of the
    project - to do it as simply as possible or just to create something cool. Anyway, more
    info would help.
  5. Dec 6, 2013 #4
    ImageUploadedByPhysics Forums1386382554.794336.jpg the red are the holes.
    The project requires the use of at least 2 simple machines, and 3 transformations of energy (springs, inclined planes, launchers, etc). A rube Goldberg machine is exactly what we want! The best thing to do is creatively fashion together things or use old parts from toys to move the marble.

    PLEASE I want to hear all your crazy ideas!!
  6. Dec 7, 2013 #5
    Haha, the two holes right above each other make this a lot trickier...

    Well for something like this, legos, k'nex, whatever building toys you can get your
    hand on, will help a lot with creating stuff. You could use wood and the like, but
    legos and k'nex really help with the trial/error aspect of something like this. K'nex
    has many roller coaster track pieces that could be used to carry the ball easily
    with some modifications. In fact, I think they have tracks actually designed for balls
    as well, though they are for bigger balls...Anyway, onward to some of my ideas.

    So some simple machines that can be easily implements... (These are pretty obvious,
    so you probably already figured stuff like this out). You are pretty much guaranteed to
    need an incline somewhere in your machine, being used as a ramp.You could easily use
    a falling mass connected to a pully to directly lift a platform with the marble. Once it
    reaches a certain height, the platform would hit a stopper on the very edge such that
    it tilts forward (sorry about the bad descriptions). Something like this is fairly common,
    so you could try something like the apparatus in this image.


    So essentially, a green spring is held down as a mass falls downward. As it falls, the
    spring is stretched. Once the mass has reached the ground, the mechanism holding
    down the spring is released, while a mechanism locks the spring on the other end.
    As the spring restores itself, a pulls a string that drags a platform forward, pushing
    the marble along. I have no idea how effective this would be - the stronger the spring,
    the faster the marble will move. But then you would need a heavier mass to deal with
    the larger restoring force. Also, construction would be tricky :P.

    I don't have an image for this one, so it'll be harder to understand. Anyway, a marble
    could roll down a ramp into a......spoon like extension? The extension would be attached
    to an threaded axle. The velocity of the marble would cause the spoon-like extension
    to begin spinning in a circle. Similar to a wing-nut, it would slowly rotate downward, like
    a wing-nut would on a threaded rod. At the bottom, it would hit another ramp, upon
    which the marble would roll out. Hope that makes sense!

    Anyway, thats all I can think of now.....I hope I helped! :)

    Edit: Realized I didn't even overview a simple system. Something pretty simple would
    be a launching mechanism (Spring or falling mass) connected to a lifting mechanism
    (another falling mass or an incline). From there, you can just have it roll right back
    to the exit hole. Once you have that, you can stick in all sorts of other stuff.
  7. Dec 7, 2013 #6
    The requirement that the marble starts at the lower hole with basically no velocity means there must a source of energy in the box. That could be a falling mass. Its fall must be triggered by the marble.

    I have put together a sketch of a possible machine. See attached.

    Attached Files:

  8. Dec 7, 2013 #7
    These ideas are GREAT! I really appreciate you guys' help. I'm amazed at the elegance, and they are sparking some of my own ideas, too.

    I am not done yet though, so ideas are still MORE than welcome from anyone else.
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