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An engineering question...

Discussion in 'Jokes and Humour' at netrider.net.au started by jd, Sep 1, 2006.

  1. A 20 ton Hyundai Digger is on top of a flatbed trailer and heading east on Interstate 70 near Hays, Kansas. The extended shovel arm is made of high tensile steel and the approaching overpass is made of commercial-grade concrete, reinforced with 1 1/2 inch steel rebar spaced at 6 inch intervals in a crisscross pattern layered at 1 foot vertical spacing.

    Solve: When the shovel arm hits the overpass, how fast do you have to be going to slice the bridge in half? (Assume no effect for headwind and no braking by the driver...)



    Extra Credit: Solve for the time and distance required for the entire rig to come to a complete stop after hitting the overpass at the speed calculated above.

    [img:640:482:593ce3f7c7]http://img171.imageshack.us/img171/1219/digger1yt0.png[/img:593ce3f7c7]
    [img:641:483:593ce3f7c7]http://img354.imageshack.us/img354/8818/digger2hi2.png[/img:593ce3f7c7]
    [img:643:483:593ce3f7c7]http://img378.imageshack.us/img378/1664/digger3nu5.png[/img:593ce3f7c7]
     
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  2. :shock: :shock:
    Whoa...
     
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  3. I haven't a clue of the answer but THAT IS SO COOL!
     
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  4. Hmmm, I think teh company who built that bridge are in trouble.....what reinforcing?!!??!
     
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  5. 205.388 kilosquackles
     
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  6. ...looks like someone used the wrong emperial to metric conversion again. It's the lack of attention to detail that will get you in the end... :LOL:

    Answers:

    a) 4.32134 kilo kips mm/ft lbs Nm s divided by (%maximum compressive strength-1)x9.8 x weight of rig x XSA of shovel arm planar area projected onto bridge seconds :LOL:

    b) The answer is infinity, because there's no !@#@!$% way the driver would hang around. The prime mover would have destructively decoupled allowing the driver to do a runner! :bolt:
     
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  7. must have been going at a decent speed to make the arm poke through the road like that!!

    i'm guessing the driver is in DEEEEEEEP SHIIIIIIIIIT!
     
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  8. Hoohoo that's expensive.
     
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  9. Time of impact over distance travled minus defication time multiplied by two.

    the driver would have shat himself instantly and all variables are directly related to that.

    Skid mark length is a constant variable and does not effect the equation.

    Job satisfaction can be extremely satisfying to non-existant with a risidual effect.

    The driver changed his dealer, that was one bad trip.

    Bin Laden claims responsability.

    GWB threatens to build a by-pass

    Splinter groups use side roads

    The bridge is impeached for undue penetration of a minor. (miner, get it?)
     
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  10. 30 seconds with google yields this and this both contain further info about this juict morsel.
     
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