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I am trying to figure out how much force i need to pull to drag an

  1. Aug 12, 2012 #1
    I am trying to figure out how much force i need to pull to drag an object with a given surface 1634 square inch and weight from a given depth. Between 100 - 200 m 11-21kg psi. However I do not know how to use Newtons laws correctly in this senario. The object does not the to accelerate. Can you please help me to understand?

    Last edited: Aug 12, 2012
  2. jcsd
  3. Aug 12, 2012 #2


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    Staff: Mentor

    Re: Fishing

    You need the volume, too, as it is relevant for buoyancy.
    Do you pull it vertically? In this case, add the weight (mass of object * gravitational acceleration) and the water resistance, and subtract buoyancy (density of water * volume of object * gravitational acceleration).

    Water resistance (drag) depends on your object and the velocity. If you want to calculate the minimal force required to lift the object (and if you are patient enough), ignore this part, the resistance will be very small if the velocity is small. For high velocities, this is the most important part.
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