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Simple Steps to Solving Force-Related Problems

  1. Mar 22, 2006 #1
    This is actually from my teacher, he's a genius, and it works pretty much every single time :-)

    No matter what situation... Draw a force-body diagram for every mass/object/thing that has a force acting on it.

    The sum of the forces in each direction in a SINGLE FORCE-BODY diagram always adds to be zero.

    Forces always come in pairs.

    Label all forces and write the equation (if applicable) for each force.
    Example: W = mg, T​

    The net force of the system, if it is accelerating will be defined by the sum of all the forces on the system, F=ma.
    To know when to add or subtract forces, make sure you understand forces are vectors and choose one direction as positive and the other as negative.​

    Follow these rules, steps, guidlines, and you will be able to solve any force-related problem!

    Hope this helps :-)

    PS: Add comments if you want
  2. jcsd
  3. Mar 22, 2006 #2
  4. Mar 23, 2006 #3


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    I believe you have just contradicted yourself here. Make sure your you specify you conditions, the former would be true only if the object is at equilibrium, i.e. stationary or moving with a constant velocity.

    I was just wandering what you meant by single force-body diagram?

  5. Mar 23, 2006 #4

    Chi Meson

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    Incorrect. This is true only for an object in equilibrium.

    [Edit: Sorry, I didn't see Hoot's response]
    Anyway, this is a forum for people to ask questions.

    This is not a place for one to post gems of wisdom. You can do that in a PF journal. Find the "Journal" tab at the top of the list. OTherwise, offer your help in response to specific questions here.​
    Last edited: Mar 23, 2006
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