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Homework Help: Raising a block

  1. Sep 27, 2011 #1
    This is more a question about how the problem is written, rather than a question about how to do the problem


    Why do they ask for tan γ in terms of d/l and h/l, rather than d and h? Is there some relation that I'm just not seeing? I'm pretty sure I know how to do the problem in terms of d and h, but the d/l and h/l terms are throwing me off
  2. jcsd
  3. Sep 27, 2011 #2
    Welcome to PF, Expat09.

    If you look at all the rest of the terms, all of them are dimensionless. By this I mean, they have no units.

    [itex] \theta[/itex] is in radians, which are dimensionless
    [itex] \alpha[/itex] and [itex] \beta[/itex] are just constants to scale h and l.

    Therefore, to make h and d dimensionless, the author chose a common length, l, to make it so there are no units for d/l and h/l.

    Does this help at all?
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