(Solved): a) A cylinder of mass m is initially at a velocity vo in a horizontal tube whose inner surface i ...

a) A cylinder of mass $m$ is initially at a velocity $v_o$ in a horizontal tube whose inner surface is covered by a viscous oil of film thickness $h$. The diameter and length of the cylinder are $D$ and $L$, respectively. Assuming a linear velocity profile in the oil film, determine an equation for the time as a function of velocity. b) A cylinder of mass $m$ slides down from rest in a vertical tube whose inner surface is covered by a viscous oil of film thickness $h$. If the diameter and height of the cylinder are $D$ and $L$, respectively, derive an expression for the velocity of the cylinder as a function of time, $t$. Discuss what will happen as $t??$. Can this device serve as a viscometer (see $\mathrm{p}$. 55)? a) b)