Question

7. A hydraulic lift of the type commonly used for greasing automobiles consists of a 10-in diameter ram which slides in a 10.006-in diameter cylinder (see figure). The annular space

is filled with oil with a kinematic viscosity of 0.0038ft?/s and specific gravity of 0.76. If the rate of travel of the ram is 0.5fps, find the frictional resistance when 6-ft of the ram is engaged in the cylinder. [DS]

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