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Homework Help: Force vector on falling object to determine terminal velocity and to graph it

  1. Dec 3, 2011 #1
    1. The problem statement, all variables and given/known data

    ScreenShot2011-12-03at11613PM.png
    k: constant
    v: velocity
    m: mass
    g: gravity
    View attachment qw.pdf

    2. Relevant equations

    Vt= √(2mg/CρA)
    F=ma

    3. The attempt at a solution
    part a. ScreenShot2011-12-03at11640PM.png
    View attachment w.pdf
    part b. ScreenShot2011-12-03at11518PM.png
    View attachment b.pdf
    I do not know if i am doing this right and i do not understand how to do part c. If you know how to do this please explain
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Dec 3, 2011 #2

    BruceW

    User Avatar
    Homework Helper

    Welcome to the forum! You've got part (a) correct.

    But for part (b), I don't think the equation Vt= √(2mg/CρA) is relevant. You were explicitly given that FR=-kv, so this is the equation you should be using. In fact, I think you got the answer for (b), before you started using that other equation for the terminal velocity.

    Part (c) is a bit trickier. You could either roughly draw what happens, or explicitly calculate the form of the graphs, then draw them.
     
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