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Real world testing bench - trying to check my calculations

  1. Dec 14, 2009 #1
    I know this seems like a homework question but the last time I was in a physics class was <ahem> 1982.

    For product testing reasons, I have fabricated a (rough, very rough--no laughing at the fabrication/welding) 'repeating pendulum hammer'. Please see "test rig diagram.jpg"

    Distance from A to B is 13.5"
    Weight of (C) Hammer (pendulum) is 10 pounds

    C is raised 90 degrees and then dropped to strike B (30/minute - fyi)

    I am assuming away all frictions, incorrect/incomplete angles and time issues.

    I believe/calculated the instantaneous force (in pounds/force) at B, exerted by the hammer (C) to be in the range of 360 to 420.

    This Rube Goldberg was conceived on a bar napkin talking with a ME. Do the forces fall in that range?


    Attached Files:

    Last edited: Dec 14, 2009
  2. jcsd
  3. Dec 19, 2009 #2
    How did you get this force range?

    The important thing here is the deceleration of the 'hammer'. This is in general tough to calculate...you might get close if you can find the elasticity of the target (assuming the 'hammer' is a hard metal).
  4. Dec 19, 2009 #3


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    Science Advisor

    What exactly are you trying to achieve with your test? I do this stuff for a living, so I am always interested.
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