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What is this old aparatus?

  1. Mar 7, 2013 #1
    I'm a student teacher, practicing some physics teaching in a new classroom with old stuff in it. My teacher associate and I can't figure out exactly what this thing is.

    There's a coil, with a small electrode strip coming off the top, a pulley up at the top, a manual latch up at the top to let the carriage drop down, some dampening tubes for the landing, and a stack to add weights to at the bottom of the carriage. It can be used for PE -> KE conversion type labs, but I'm not sure what the point of the coil/electricity is?? We plugged it in for fun, unfortunately there were no cool sparks or anything ( ;-) ) But the coil did buzz, and the electrode vibrated.

    There's also a non-working tesla coil in the class, which I haven't taken out of the cabinet yet, and the teacher hasn't attempted to troubleshoot or fix yet - anyone with experience with these things?
  2. jcsd
  3. Mar 11, 2013 #2
    no ideas?
  4. Mar 11, 2013 #3


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  5. Mar 11, 2013 #4
    beauty, thanks. Seems similar to a Gaertner Freefall aparatus, (I assumed it was something to do with freefall, but didn't get the wording right in my searches) - and the coil is likely an electromagnet, used to measure acceleration somehow. I'm off on a good enough start now - thanks!!
    I'll report back when I figure out a good way to use it.

    Any ideas on repairing a tesla coil?
  6. Mar 11, 2013 #5
    Does look like the that aparatus you mentioned. THe pulley would allow you to do an Atwood machine in addition to freefall.
  7. Mar 11, 2013 #6


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    The coil maybe a sparker can you find a way to feed a strip of waxed paper through it?
  8. Mar 11, 2013 #7
    I think so... I'll have to check again tomorrow. I think the "electrode" at the top, upon remembering what it did when we plugged it in, vibrated back and forth between the electromagnet, hence creating a sine-wave on a paper strip as it dropped down.
    And yes, the pulley for use in an atwood setup certainly makes sense!! I think we've pieced enough of this together - hopefully tomorrow I can play with it.
  9. Mar 11, 2013 #8
    Are you sure it's a coil and not a solenoid on the apparatus? If it is a solenoid it may be a rig to evaluate push/pull force. A force push-pull gauge.
  10. Mar 11, 2013 #9


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    Our paper tape sparkers left a spot for each spark, measure the distance between, and assume a 60hz spark.
  11. Mar 11, 2013 #10
    I think it's an electromagnet being activated at ~60hz (by the sounds of it), which simply makes the 'actuator' strip vibrate back and forth in it's space. The strip is pretty thin and somewhat flexible, but it does show discoloration a bit like overheated metal - but no obvious signs of sparking. I'll report more tomorrow.
    Isn't physics fun?
  12. Mar 11, 2013 #11
    The flat piece of metal at the top looks like it has two screws or rivets in it. They seem to be holding a metal tab that points toward the middle. Maby this holds the falling portion at the top till you pull the tab out from under it.

    Something does seem wierd though. The outer larger tubes serve to support the top of the apparatus and guide the falling part. The smaller inner tubes on the piece that falls seem to fit into two other tubes at the bottom with a rather snug fit. How does this tube fall into the proper place?
  13. Mar 11, 2013 #12
    Yes - at the top is a release mechanism.

    The inner tubes: there are solid rods on the carriage with rounded/beveled ends to guide them into the tubes. Because they are a relatively tight fit, they serve as dampeners.
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