17. A cylindrical capsule can move inside a long vertical cylindrical tube filled with a viscous Newtonian liquid. Diameter of the capsule is slightly smaller than the inner diameter of the tube and...

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Extracted text: 17. A cylindrical capsule can move inside a long vertical cylindrical tube filled with a viscous Newtonian liquid. Diameter of the capsule is slightly smaller than the inner diameter of the tube and walls of the capsule have negligible thickness. Drag force on the capsule is proportional to speed of the capsule. If the capsule is empty, it rises up with a uniform velocity v and if the capsule is completely filled with the liquid, it moves down with a uniform velocity U2. (a) Find expression of velocity of the capsule if n fraction of its volume is filled with the liquid. (b) How will the above relation change, if the n fraction of volume of the capsule is filled with another liquid, density of which is k times of that of the liquid in the tube? すこ し1-en)