Chapter 3, Problem 3.64P

(a)

Interpretation Introduction

Interpretation:

The mass of air in a person ‘slungs at atmospheric conditions is to be calculated.

Concept Introduction:

The equation of states for an ideal gas is:

  $PV=nRT$   ......(1)

Here, $P$ is the pressure, $V$ is the volume, $T$ is the temperature of the system, and $n$ is the number of moles of gas present in the system. $R$ is the universal gas constant.

Number of moles, $n$ is defined as:

  $n=\frac{m}{\text{MW}}$   ......(2)

Here, $m$ is the given mass of the gas and $\text{MW}$ is the molecular weight of the gas.

(b)

Interpretation Introduction

Interpretation:

The mass of air in a person’s lungs at the depth of $40\text{ m}$ below the ocean surface is to be calculated.

Concept Introduction:

The equation of states for an ideal gas is:

  $PV=nRT$   ......(1)

Here, $P$ is the pressure, $V$ is the volume, $T$ is the temperature of the system, and $n$ is the number of moles of gas present in the system. $R$ is the universal gas constant.

Number of moles, $n$ is defined as:

  $n=\frac{m}{\text{MW}}$   ......(2)

Here, $m$ is the given mass of the gas and $\text{MW}$ is the molecular weight of the gas.

Pressure at a point due to the weight of a fluid above it is known as hydrostatic pressure and it is calculated by,

  $P_H=\rho gh$   ......(3)

Here, $\rho$ is the density of the fluid, $h$ is the height of the fluid above the point at which the pressure is to be calculated, and $g$ is the acceleration due to gravity.

(c)

Interpretation Introduction

Interpretation:

The mass of gas mix in a person’s lungs at the depth of $300\text{ m}$ below the ocean surface is to be calculated.

Concept Introduction:

The equation of states for an ideal gas is:

  $PV=nRT$   ......(1)

Here, $P$ is the pressure, $V$ is the volume, $T$ is the temperature of the system, and $n$ is the number of moles of gas present in the system. $R$ is the universal gas constant.

Number of moles, $n$ is defined as:

  $n=\frac{m}{\text{MW}}$   ......(2)

Here, $m$ is the given mass of the gas and $\text{MW}$ is the molecular weight of the gas.

Pressure at a point due to the weight of a fluid above it is known as hydrostatic pressure and it is calculated by,

  $P_H=\rho gh$   ......(3)

Here, $\rho$ is the density of the fluid, $h$ is the height of the fluid above the point at which the pressure is to be calculated, and $g$ is the acceleration due to gravity.