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Homework Help: Finding Applied Force with Free Body Diagrams (Grade 12 Physics)

  1. Apr 1, 2012 #1
    1. The problem statement, all variables and given/known data

    You have a 10kg object that is thrown down a building. The distance from the ground to the building is 50m. The initial velocity of the object is 5 m/s. What is the applied force and what force does the object hit the ground with?

    2. Relevant equations

    Fapp= Fnet+Fg
    Fnet=acceleration x mass

    3. The attempt at a solution
    I don't even know where to start on this question. I don't think I can assume the acceleration of the object is 9.81 m/s/s because it is thrown down not dropped. Without acceleration I can't find Fnet. Without Fnet I can't find Fapp. All I know is Fg=mass(g)= 98.1N. Can someone help me on this?
  2. jcsd
  3. Apr 1, 2012 #2


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    While the throw does indeed apply a force to the object, what happens after the object leave the throwing hand? Is the force still being applied?
  4. Apr 1, 2012 #3
    I would suppose the force isn't being applied anymore. Huh never even thought of that. Is there a way to find out the applied force on the object when it was first thrown?
    If the force is being applied anymore that would make Fnet=Fapp-Fg=-98.1N. Right? Making acceleration -9.81m/s/s, but that is wrong right? Because it's being thrown down. Now I don't know what think.
    If the force of gravity is the only force acting on it after being thrown would that make the force that the object hits the ground with Fg?
    Last edited: Apr 1, 2012
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