$\"\"$

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Natural length of the spring is $\"\"$ cm.

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Force required to stretch it to $\"\"$ cm from its natural length is $\"\"$ N.

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Hookes law: $\"\"$ , where $\"\"$ spring constant.

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$\"\"$ is force required to maintain a spring stretched $\"\"$ units beyond its natural length.

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Here $\"\"$ N and $\"\"$ cm $\"\"$ m.

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$\"\"$

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Therefore, spring constant $\"\"$ N/m.

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Consider $\"\"$ .

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Work done formula:

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

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Determine the work done in stretching the spring from its original length to $\"\"$ cm.

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Here $\"\"$ and $\"\"$ cm $\"\"$ m.

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$\"\"$

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$\"\"$

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$\"\"$ J.

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Work done required is $\"\"$ J.

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$\"\"$

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Work done required is $\"\"$ J.