$\"\"$

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Work required to stretch a spring $\"\"$ inches from its natural length is $\"\"$ foot-pounds.

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Work done by the object in moving from $\"\"$ to $\"\"$ is $\"\"$ .

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Hooks law: $\"\"$ .

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$\"\"$

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Here $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$

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Find the work required to stretch the spring an additional $\"\"$ inches.

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Therefore $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ .

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Therefore, work required to stretch the spring an additional $\"\"$ inches is $\"\"$ .

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$\"\"$

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Work required to stretch the spring an additional $\"\"$ inches is $\"\"$ .