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I really need help

  1. Mar 27, 2008 #1
    [SOLVED] I really need help

    I understand the very simple questions and all, but when the book throws all these extra things at me, I get so lost. You might've remembered my earlier post (my first one), so I'm back with a bit more.

    Code (Text):
    If it takes a human cannonball 1.5s to exit a 1.6m long cannon, what is the average net force acting on the performer if his mass is 65kg?
    I tried using a a=[tex]\frac{v_{2}-v_{1}}{t}[/tex] equation, but that wouldn't work. I also tried the d = v t equation, but that wouldn't work either. I'm assuming I still use Fnet = ma for this.

    For you answers could you also tell me why that works? Thanks a lot

    EDIT: Additionally, I just read the sticky, and if a mod feels that it should belong in the homework section, please feel free to move it; but it's not really homework, as I'm just studying for a test.
     
    Last edited: Mar 27, 2008
  2. jcsd
  3. Mar 27, 2008 #2

    olgranpappy

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    use
    [tex]
    x=\frac{1}{2}a t^2 + v_0 t + x_0
    [/tex]

    and F=ma
     
  4. Mar 27, 2008 #3
    I'm still having trouble putting the formula together. I filled in the t's with the 1.5, but I've never heard of v_0... I've heard of v_1 though. Additionally, how is there an x on both sides of the equation?
     
  5. Mar 27, 2008 #4

    olgranpappy

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    v_0 is the initial velocity, which is...

    x_0 is the initial position, which is...

    x is the final position, which is...
     
  6. Mar 27, 2008 #5
    Ok, I finally got it. You're equation helped a little, but I was still confused by it. The final equation was d = 1/2at^2

    Thanks a lot for the effort... I really don't think I'm going to do well on this test :cry:
     
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