illustrate the difference between a neutral object, a positively charged object, and a negatively charged object

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Ways that industry and agriculture use physical properties to separate substances

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?