Unformatted text preview: 7.60. Set Up: Applying with the change in mechanical energy is simply the differ ence between the initial and final elastic potential energy of the stretched spring: Also define the initial position as the point of release and the final position as the lowest position after five complete cycles. Figure 7.60 Solve: (a) (b) The percentage lost is Reflect: Note that the spring, in its equilibrium position, is stretched by the weight of the hanging mass. Conse quently, an alternative solution can be developed that explicitly incorporates gravitational potential energy. Let d be the distance the spring is stretched at equilibrium due to the weight of the object. Define a new reference point; let where the mass is 0.130 m below the equilibrium point. At this point, the spring is stretched The total potential energy is therefore: Then when the mass is 0.100 m below the equilibrium position, and the spring is stretched The total energy is then: The change in mechanical energy is thus the same as found in the simplified calculation of...
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 Spring '07
 Shoberg
 Energy, Kinetic Energy, Potential Energy, Work, Emech

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