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Homework Help: I can't be this dumb. can i?

  1. Feb 24, 2005 #1
    only two horozontal forces act on a 3kg mass. one force is 9.0 N acting due east, and the other is 8.0 N acting 62 degrees north of west. what is the magintude of the body's acceleration.

    The answer in the book is 2.9 m/s^2. but how can this be?

    shouldn't the solution be (9 + 8cos(118))/3 = 1.74808 m/s^2 ?
  2. jcsd
  3. Feb 24, 2005 #2
    you are missing a component of the force

    Sure you got that first part right but you're missing the fact that there is ANOTHER COMPONENT of force being appleid on this object. You decomposed that 8N force in 8cos 62 and 8sin62 what hapopened to the 8sin62?
  4. Feb 24, 2005 #3
    What about the northward component of the second force?

    The book's answer is correct.
  5. Feb 24, 2005 #4
    damn is all i can say
  6. Feb 24, 2005 #5


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    Homework Helper

    You can deal with x and y components separately as you did, or you can use trigonometry to add the two force vectors.
  7. Feb 25, 2005 #6


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    Science Advisor

    "i can't be this dumb. can i? "

    Don't ask questions like that! You might not like the answers!
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