A block of mass m start at rest at height h on a frictionless inclined plane. The block slides down to plane, travels across a rough horizontal surface with coefficient of kinetic friction and compresses a spring with force constant k a distance x before momentarily coming to rest. Then the spring extends and the block travels back across the rough surface, sliding up the plane. The block travels a total distance d on rough horizontal surface. The correct expression for the maximum height h that the block reaches on its return is:
| A. |
`mgh'=mgh-mumgd` |
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| B. |
`mgh'=mgh+mumgd` |
| C. |
`mgh'=mgh+mumgd+kx^2` |
| D. |
`mgh'=mgh-mumgd-kx^2` |