physics help....

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13

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  • SofaKingRad
    SofaKingRad Posts: 1,592 Member
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    there isnt a picture to post... i could like draw it out and kinda show you what i THINK it is asking... or do you need a picture of the force table???

    No, I don't need a picture of hte force table now. I think I know what it's asking. I think it's in Quadrant 3, just intuitively because the two forces that you know are there are in Quadrant 1. Equal and opposite reaction shows that the opposit reaction would be roughly in quadrant 3. But, you need to prove that.

    But for a force table, the forces pull "out", not "in". Hence, they pull away from the point of intersect.
    since both forces are in the 1st quadrant, the resultant equilibrium is also in the 1st quadrant.
    The equilibrium is somewhere in between 20 and 80 degrees.

    Doesn't matter if they are pushing or pulling. The reactive force to keep it in equilibrium is 180 degrees from the resultant of the two known forces, which puts it in the third quadrant.

    Agreed. If the first two forces are pulling, the answer would only be the first quadrant if the third force was for some unexplained reason pushing. And vice versa is the first two are pushing.

    I have a BS in Physics and have never heard of a "force table." From the net:
    A force board (or force table) is a common physics lab apparatus that has three (or more) chains or cables attached to a center ring. The chains or cables exert forces upon the center ring in three different directions. Typically the experimenter adjusts the direction of the three forces, makes measurements of the amount of force in each direction, and determines the vector sum of three forces. Forces perpendicular to the plane of the force board are typically ignored in the analysis.

    Cables or chains can't push. They only pull. So the regardless of the magnitude of any of the forces, the third (equalibriant) force must pull in the third quadrant since the vector sum of the first two pulls in the first quadrant.

    I never heard of one either. I googled it. I wasn't talking about the force table itself, I was just saying that regardless if you could push or pull on it, it's still third quadrant for a resultant if it is in equilibrium.
  • index
    index Posts: 3
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    use this animation - hopefully helps: http://www.mrwaynesclass.com/teacher/Vectors/Force_Table/
  • treetop57
    treetop57 Posts: 1,578 Member
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    I never heard of one either. I googled it. I wasn't talking about the force table itself, I was just saying that regardless if you could push or pull on it, it's still third quadrant for a resultant if it is in equilibrium.

    Right. The sign of the third force would have to be the opposite of the first two forces for some reason not explained by the problem.

    In any case, Index has explained why he was saying first quadrant instead of third. He thought the question was which quadrant will the sum be in, not which quadrant the equalibrant will be in.

    For what it's worth, I'd never heard the word equalibrant before today either!
  • JPod279
    JPod279 Posts: 722 Member
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    Imagine my suprise to see this post was actually what the topic was about.
  • UsedToBeHusky
    UsedToBeHusky Posts: 15,229 Member
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    my biggest issue is like how to find force? do i automatically multiply is by 10? and if so why? I mean force= mass*acceleration, but i dont know the mass, so does that mean i cant figure it out?!

    I'm not a physics major, but my initial thought was E when reading your question. Hope you find your answer soon. :flowerforyou:
  • GasMasterFlash
    GasMasterFlash Posts: 2,206 Member
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    If anyone has any questions about long division, I'm here.
  • Changing__Christina
    Changing__Christina Posts: 247
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    Can someone please go on the record and say that my answer was just as correct as the ones with the fancy explainations! I mean, why can't a girl get props when she was the first one with the correct answer! just sayin'!
  • SofaKingRad
    SofaKingRad Posts: 1,592 Member
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    Can someone please go on the record and say that my answer was just as correct as the ones with the fancy explainations! I mean, why can't a girl get props when she was the first one with the correct answer! just sayin'!

    Girl, I'm givin' you props. Good job!
  • macpatti
    macpatti Posts: 4,280 Member
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    The resultant for must be in the third quadrant. If the 20 degree force is >> than the 80, then the force is at 200 degrees. If the 80 is >> than the 20 degree force, then the force is at 260 degrees. Either way, the combination of the forces will result with an equilibrium force in the third quadrant.
  • treetop57
    treetop57 Posts: 1,578 Member
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    It goes without saying that Changing__Christina gave the correct answer long before I did. Great job, Christina!
  • GasMasterFlash
    GasMasterFlash Posts: 2,206 Member
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    I bet you never thought a homeless hobo who smells of booze and cigarettes would discuss physics with you, huh?
    ^^^ This guy specializes in soil... ing himself.
  • DatEpicChick
    DatEpicChick Posts: 358 Member
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    I FIGURED IT OUT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    okay so i went and looked on a seperate physics website!!!

    each quadrant contains 90 degrees.

    you find the resultant by adding together the 2 angles (80 + 20)

    therefore the resultant is 100
    which lies in the 2nd quadrant

    you find the equilibrium by adding 180 degrees to that (because its oppsite)

    this equals 280, which lies in the 4th quadrant.
    thank god for other professors,
    and thank you all for helping me!
  • DatEpicChick
    DatEpicChick Posts: 358 Member
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    snapshot.png
  • Changing__Christina
    Changing__Christina Posts: 247
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    Can someone please go on the record and say that my answer was just as correct as the ones with the fancy explainations! I mean, why can't a girl get props when she was the first one with the correct answer! just sayin'!

    Girl, I'm givin' you props. Good job!

    Finally!!!! I've been trying for an hour to get credit! Copy cats!
  • Changing__Christina
    Changing__Christina Posts: 247
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    It goes without saying that Changing__Christina gave the correct answer long before I did. Great job, Christina!


    Thank you sooo much! I would like to thank my fans! :)
  • SofaKingRad
    SofaKingRad Posts: 1,592 Member
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    snapshot.png

    Soooo the resultant force is in the first quadrant.....equal and opposite of that would be the third quadrant....not the fourth.
  • DatEpicChick
    DatEpicChick Posts: 358 Member
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    ****.
  • Changing__Christina
    Changing__Christina Posts: 247
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    I FIGURED IT OUT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    okay so i went and looked on a seperate physics website!!!

    each quadrant contains 90 degrees.

    you find the resultant by adding together the 2 angles (80 + 20)

    therefore the resultant is 100
    which lies in the 2nd quadrant

    you find the equilibrium by adding 180 degrees to that (because its oppsite)

    this equals 280, which lies in the 4th quadrant.
    thank god for other professors,
    and thank you all for helping me!

    I don't think this is correct. that isn't what C is! :( sorry that you were wrong!
  • DatEpicChick
    DatEpicChick Posts: 358 Member
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    TO GET THE ANGLE I HAVE TO USE A PROTRACTOR...
    god crammit.
    this shouldnt be so difficult.

    i now understand that the answer is in the 3rd quadrant.
    but i'd like to get there you know? hahahahaa
  • GasMasterFlash
    GasMasterFlash Posts: 2,206 Member
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    Seriously, why are you stressing this? What's the worst that could happen?

    Guy_inside_building_collapse.gif

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