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Homework Help: One Dimensional Force Problem

  1. Feb 9, 2010 #1
    1. The tension at which a fishing line snaps is commonly called the line's “strength.” What minimum strength is needed for a line that is to stop a salmon of weight 87 N in 11 cm if the fish is initially drifting horizontally at 3.3 m/s? Assume a constant deceleration.

    2. F=ma, W=mg

    3. I have a feeling this problem is really easy I just don't know how to do it. I thought I did it correct below but my answer is wrong. Can someone help me please?

    W=87N d=0.11m a+3.3m/s
    m=87/9.8= 8.89kg
    F=(3.3m/s)(8.89kg)= 29.3N
  2. jcsd
  3. Feb 9, 2010 #2
    I don't really understand how this can be a one-dimensional problem.
    If it is, you first have to find the acceleration using what is given. ie.
    Final velocity = 0
    Initial velocity = 3.3 m/s
    Displacement = 0.11 m
    Try v2 - u2 = 2*a*s to find out the acceleration and multiply it with the mass of the body under consideration.
  4. Feb 10, 2010 #3
    Oh okay. I had no idea I had to relate those equations. Is my mass that I have above correct?
  5. Feb 10, 2010 #4
    So I just tried it and still got it wrong. Here's what I did.

    a= 3.32/0.22= 49.5
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