Answers (cont.)
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2.) Since position #2 is half
way down total energy will be
half in PE and half in KE
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So…KE at position #2 will be
half that at position #3
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So…KE at position #2 is
78.125J
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Then use KE (at #2)=78.125J
=1/2 x 0.5kg x v
2
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v=17.68m/s at position #2