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Homework Help: Pull tab of beverage containers

  1. Aug 27, 2008 #1
    Beverage engineering. The pull tab was a major advance in the engineering design of beverage containers. The tab pivots on a central bolt in the can's top. When you pull upward on one end of the tab, the other end presses downward on a portion of the can's top that has been scored. If you pull upward with a 10N force, approximately what is the magnitude of the force applied to the scored section? (You will need to examine a can with a pull tab.)

    After I measure the pull tab, I got:
    Pull tab length is 2.5cm
    From pulling zone to pivot is 1.75cm, let it = R
    and from pivot to pressing zone is 0.75, let it = r

    Given, pull upward 10N

    Can I calculate by using
    F1R = F2r
    10 * 1.75 = 0.75 * F2
    Fpressing = 23.33N

    Is this correct?
  2. jcsd
  3. Aug 27, 2008 #2


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    Yes it's correct, given the numbers you have for R and r.
  4. Aug 27, 2008 #3


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    did i hear the sound of a beer can being opened … ?

    Hi noppawit! :smile:

    Looks good!

    It's a lever, so the gearing is the ratio of the lengths …

    hmm … now pull one for me! :wink:

    EDIT: oh … and one for Redbelly98 too! :biggrin:
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