Chapter 4, Problem 4.20P

(a)

Interpretation Introduction

Interpretation:

The value of average velocity which is relative to the bottom of the tank for the given condition should be calculated.

Concept Introduction:

Average velocity is related with the area and the volume displaced by rod. The relationship is given by formula,

  ${\stackrel{·}{\text{V}}}_P\text{=}{\text{A}}_{\text{p}}{\text{v}}_{\text{p}}$

Where,

  ${\text{A}}_{\text{p}}$ is the area.

  ${\text{A}}_{\text{p}}=\frac{\pi }{4}{\text{d}}_{\text{p}}^{\text{2}}$

  ${\text{V}}_{\text{P}}$ is the volume displaced by rod.

  ${\text{v}}_{\text{p}}$ is the average velocity.

For the case of incompressible fluid, the density remains constant with the flow of velocity. Thus,

  $v_{\text{P}}\text{=}\text{V}$

Volume placed by the rod is equal to the volume of water moving by the rod.

(b)

Interpretation Introduction

Interpretation:The value of average velocity which is relative to the advancing rod for the given condition should be calculated.

Concept Introduction:

Average velocity is related with the area and the volume displaced by rod. The relationship is given by formula,

  ${\stackrel{·}{\text{V}}}_P\text{=}{\text{A}}_{\text{p}}{\text{v}}_{\text{p}}$

Where,

  ${\text{A}}_{\text{p}}$ is the area.

  ${\text{A}}_{\text{p}}=\frac{\pi }{4}{\text{d}}_{\text{p}}^{\text{2}}$

  ${\text{V}}_{\text{P}}$ is the volume displaced by rod.

  ${\text{v}}_{\text{p}}$ is the average velocity.

For the case of incompressible fluid, the density remains constant with the flow of velocity. Thus,

  ${\text{V}}_{\text{P}}\text{=}\stackrel{\cdot }{\text{V}}$

Volume placed by the rod is equal to the volume of water moving by the rod.