$\"\"$

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The point masses are $\"\"$ , $\"\"$ , $\"\"$ and $\"\"$

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The points are $\"\"$ , $\"\"$ , $\"\"$ and $\"\"$ .

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The definition of moment is $\"\"$ and $\"\"$ .

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Substitute $\"\"$ , $\"\"$ , $\"\"$ and $\"\"$ and $\"\"$ , $\"\"$ , $\"\"$ and $\"\"$ in the definition of moment formula.

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Find $\"\"$ .

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$\"\"$

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$\"\"$ .

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Find $\"\"$ .

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$\"\"$

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$\"\"$ .

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The moment of the mass $\"\"$ and $\"\"$ .

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$\"\"$

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Total mass : $\"\"$ .

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$\"\"$

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$\"\"$ .

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Center of the mass: $\"\"$ and $\"\"$ .

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Substitute $\"\"$ and $\"\"$ and $\"\"$ in the above formulals.

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$\"\"$

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$\"\"$

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$\"\"$

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Center of the mass is $\"\"$ .

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$\"\"$

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The moment of the mass $\"\"$ and $\"\"$ .

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Center of the mass is $\"\"$ .