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Homework Help: Velocity vs. time

  1. May 19, 2008 #1
    On a graph such as below:

    http://www.gcsescience.com/Velocity-Time-Graph-Rocket.gif [Broken]

    Would the graph of resultant force vs. time be of a shape similar to the curve of "y=1/x" in the positive quadrant? I make this assumption, since the gradient of the v vs. t graph is decreasing, therefore the acceleration is decreasing. I also think that the rate of change of acceleration is decreasing.

    Thanks
     
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. May 19, 2008 #2
    No, 1/X is curve that starts with a high y value and decreases quickly and then levels off from left to right. Look at the slope....in the v vs. t graph velocity is increasing over time because it is in the positive quadrant. Acceleration is increasing a lot at first and is leveling off at a positive number based on the slope of the graph.
     
  4. May 19, 2008 #3
    What would be the shape of the graph then? I think it would be a curve, but dont know the shape.

    Thanks
     
  5. May 19, 2008 #4
    The graph shown is a log x graph. The graph of its slope, aka the acceleration, will start positive maybe (0, 2) then will decrease and level off until it is pratically zero at every value after a certain time. This being the derivative would be the (1/X) curve, but for the derivative not the graph shown....Well guess that does it for this problem. Hope that helps. Ross
     
  6. May 19, 2008 #5
    nokia8650,

    Your original answer is correct. The only criticism I have is that the slope doesn't appear to me to be infinite at the origin.
     
  7. May 19, 2008 #6
    And it's not a log graph.
     
  8. May 20, 2008 #7
    Thanks, yes, I only meant the shape of it, as it is hard to describe! Thanks alot
     
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