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Homework Help: What is the train's final speed?

  1. Oct 29, 2008 #1
    1. The problem statement, all variables and given/known data

    Hey guys..
    A train traveling at 40km/h accelerates at a rate of 5.0m/s^2 for 0.80s.what is its final speed.

    2. Relevant equations[/b
    i belive this is the equation a=v1-v0/t


    3. The attempt at a solution
    Im totally stuck i tried but due to a lack of ti 84 i cant get the calculations...Please help
     
  2. jcsd
  3. Oct 29, 2008 #2
    One thing you need to notice is that the initial speed is in km/h and the acceleration is in m/s^2 so I would adjust the initial velocity to be in m/s.
     
  4. Oct 29, 2008 #3
    40 km/h = 11.1 m/s

    Now Use this equation: Vf = Vo + at to solve for Vf.
     
  5. Oct 29, 2008 #4
    so it would be Vf=0+5.0(.80)
    which equals 4 so the answer would be 4km/h? im sorry you know the units?
     
  6. Oct 29, 2008 #5
    Vo is 11.1 m/s, not 0. And the units are m/s.
     
  7. Oct 29, 2008 #6
    thanks allot so heres my answer

    v=11.1+5.0(.80)
    4+11.1
    15.1m/s?
     
  8. Oct 29, 2008 #7
    As far as I can tell, that looks good.
     
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