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Is xf=xi +vixΔt accurate?

  1. Apr 9, 2012 #1
    1. The problem statement, all variables and given/known data

    Is the following formula accurate?: xf=xi +vixΔt
    This question is for the hypothesis in our lab report. If we solve for the xf experimentally (in the lab), will the answer we get be the same if I do it mathematically. If so, why?

    2. Relevant equations
    xf=xi +vixΔt
    to solve for Δt, use: yf = yi + viyΔt + 1/2a Δt^2
    vix is solved in the first part of the experiment...

    3. The attempt at a solution
    The following formula is accurate as the x velocity is constant, thus whatever distance traveled, the distance traveled will be the same per second. What else can I say about it?
     
  2. jcsd
  3. Apr 9, 2012 #2

    BruceW

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    Yep. Maybe you are supposed to think of some reasons why the x velocity is not exactly constant in the experiment.
     
  4. Apr 9, 2012 #3
    Thank you for responding. I need to say why the answers for xf will be the same (mathematically and experimentally). The vix is always constant, according to our teacher (air resistance is negligible).
     
  5. Apr 9, 2012 #4

    BruceW

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    Then maybe you are supposed to talk about why the equation is true given that the velocity is constant. Do you know much about calculus?
     
  6. Apr 9, 2012 #5
    maybe, and I will be learning calculus next year. Why do you ask?
     
  7. Apr 9, 2012 #6
    How can I explain that the equation is true?
     
  8. Apr 9, 2012 #7

    BruceW

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    Well, you are given that the speed is constant, and how (in calculus) are speed and position related?
     
  9. Apr 9, 2012 #8
    I am not too sure... How are they related? Is it because there is no acceleration in the x-direction so speed and position are related proportionally, so to speak? This is a guess.
     
    Last edited: Apr 9, 2012
  10. Apr 9, 2012 #9

    BruceW

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    pretty much, but if you haven't done calculus, then I don't think you'd be expected to give this kind of answer. Maybe you are supposed to say why there is no acceleration in the x-direction, like why the air resistance doesn't affect the outcome in this case.
     
  11. Apr 9, 2012 #10
    Ok thank you, I will do my best. Thank's for the assistance!
     
  12. Apr 9, 2012 #11

    BruceW

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    no problem!
     
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