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Homework Help: Finding Velocity

  1. Mar 13, 2013 #1
    1. The problem statement, all variables and given/known data

    Given the Information in the attachment and
    m = 5.0 kg

    a) find how far the mass moves before stoping
    b) find it's velocity at t = 5.0s

    i only need help on part B

    Information i found from part A
    distance = 4.72 meters
    work = 19.6 Joules

    2. Relevant equations

    3. The attempt at a solution

    I know you need to use Vo which is 2.8 m/s but I dont know what formula to use.

    I was about to use:

    v = vo + at

    but i have no acceleration.

    please help.

    Attached Files:

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    Last edited: Mar 13, 2013
  2. jcsd
  3. Mar 13, 2013 #2

    rude man

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    Gold Member

    I got a slightly different number for distance traveled.

    acceleration: how about F/m? And remember signs ...
  4. Mar 13, 2013 #3
    ah i completely forgot about

    F = ma

    I found Force by dividing Work over Distance

    Then I used f=ma

    Found a = -0.83

    Then I used V = Vo + at

    and got V = -1.36.

    which is the answer thank you for your help

    Thank you.
  5. Mar 13, 2013 #4

    rude man

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    Yer' welcome. You could also have used F = 4.8cos30.

    (P.S. I misread F = 4.8. You got the right answer for distance as you know by now.)
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