InterviewSolution
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InterviewSolution
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Here is an example with this lesson plan: Generally you can choose any level to e the reference level, but once chosen, be consistent. A 2.0 kg sloth hangs 5.0 m above the ground (Fig. 8-23). (b) The sloth drops to the ground . For each choice of refrence point, What is the change DeltaU in the potential energy of hte sloth-Earth system due to the fall? |
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Answer» Solution :KEY IDEA The change in potential energy does not DEPEND on the choice of the refrence point for `y=0`, instead, it depends on the change in height `Delta y`.  Figure 8-23Four choices of reference point `y=0`. Each y axis is marked in units of meters. The choice affects the value of the potential energy U of the sloth-Earth SYSTEM. However, it does not AFFECT the change `DeltaU` in potential energy of the system if the sloth moves by, say, falling. Calculation: For all four situations, we have the same `Delta y = -5.0m`. Thus, for (1) to (4) , Eq. 8-48 tells US that `Delta U = MG Deltay=(2.0kg)(9.8 m//s^(2))(-5.0m)` ` = -98` J. |
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