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November 10th, 2011, 05:06 AM   #1
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Question in moment of force



I find moment of Q correct but moment of p is not correct

please I want your help.
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November 10th, 2011, 11:29 AM   #2
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Re: Question in moment of force

MQ=15N*8m=120Nm
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November 11th, 2011, 12:26 PM   #3
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The moment about Q = -15N*8m*cot(45) = -120Nm (or -120J if you like).
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November 11th, 2011, 12:29 PM   #4
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Re: Question in moment of force

Yes ... but what is moment of p ... here I face the problem
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November 11th, 2011, 12:35 PM   #5
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The moment [color=red]about[/color] P = 25N(8m) - 20N(8m) - 15N(8m) = -80Nm (or -80J if you like).

By the way, you annotated the diagram with Q at the bottom right, but Q was already in use at the top left.
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November 11th, 2011, 12:43 PM   #6
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Re: Question in moment of force

In fact I don't understand clearly how you got that answer.


I think -20(0) because it return to Q force ...

can explain to me each force by diagram please for moment of P ..
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November 12th, 2011, 08:36 AM   #7
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Since each force has a unique magnitude, you can tell which force each term refers to. Each force is multiplied by the appropriate distance, measured perpendicular to the direction of the force, and these distances are shown in the diagram (or an easy consequence of what is shown).
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