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Homework Help: Question on a ramp

  1. Jan 31, 2006 #1
    I have a 1kg weight on a rmap inclined 20degrees being pulled upwards and to the left
    ************** -
    in that motion above(look at dashes only), is it -ma or +ma?
    so the equation is

    -a = t - mgsin20
    a = t - mgsin20
    im just wondering if a leeft movement has anythign to do with gravity (A) being + or-
    Last edited: Jan 31, 2006
  2. jcsd
  3. Jan 31, 2006 #2
    try looking at it in terms of the forces acting in the X direction and the forces acting in the Y direction. Consider where you place your origin.

    Then think about which vectors will be positive and which will be negative.
  4. Jan 31, 2006 #3
    no no i just want a simple anaswre
    i just meant weather acceleration should be -ma or +ma
  5. Jan 31, 2006 #4
    It has to do with how you define coordinate system.
  6. Jan 31, 2006 #5
    i have an exam tomorrow and i just wanted to know , are you saying theres no way to tell from the info i sent?
    *sigh* nvm..
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