Chapter 17, Problem 17.38P

Interpretation Introduction

(a)

Interpretation:

Thematerial having highest value of density should be determined.

Concept introduction:

Density is defined as the ratio of mass per unit volume.

  $\text{ρ}\text{=}\frac{\text{m}}{\text{v}}$

Where,

m is the mass of material (kg)

v is the volume of material in (m³)

The unit of density is kg/m³

Interpretation Introduction

(b)

Interpretation:

The material having highest value of tensile strength should be determined.

Concept introduction:

Tensile strength is defined as the ratio of force per unit area.

  $\begin{array}{l}\text{Tensile}\text{strength}\text{=}\frac{\text{Force}}{\text{Area}}\\ \text{Tensile}\text{strength}\text{=}\frac{\text{F}}{\text{A}}\end{array}$

Where,

F is the force

A is the area

Unit of tensile strength is pascal.

Interpretation Introduction

(c)

Interpretation:

The material having highest value of elastic modulus should be determined.

Concept introduction:

Elastic Modulus is defined as the ratio of tensile stress to tensile strain.

  $\begin{array}{l}\text{Elastic Modulus}\text{= }\frac{\text{Tensile}\text{Stress}}{\text{Tensile}\text{Strength}}\\ \text{Elastic Modulus}\text{=}\frac{\sigma }{\epsilon }\end{array}$

  $\sigma$ is the tensile stress.

  $\epsilon$ is the tensile strain.

Unit of elastic modulus is pascal and psi.

Interpretation Introduction

(d)

Interpretation:

The material having highest value of melting temperature should be determined.

Concept introduction:

Melting temperature of material is defined as the temperature at which the material changes its phase from solid to liquid phase.

Unit of melting temperature is in degree centigrade.

Interpretation Introduction

(e)

Interpretation:

The material having highest value of specificmodulusshould be determined.

Concept introduction:

Specific modulus is defined as the ratio of elastic modulus of material to density of material.

  $\text{Specific Modulus = }\frac{\text{Elastic}\text{modulus}}{\text{Density}}$

  $\text{Specific Modulus = }\frac{{\text{E}}_{\text{C}}}{\text{ρ}}$

  ${\text{E}}_{\text{C}}$ is the modulus of elasticity.

  $\text{ρ}$ is the density of material

Unit of melting temperature is J/kg.

Interpretation Introduction

(f)

Interpretation:

The material having highest value of specific strength should be determined.

Concept introduction:

Specific modulus is defined as the ratio of strength of material to density of material.

  $\text{Specific Modulus = }\frac{\text{Strength}}{\text{Density}}$

  $\text{Specific Modulus = }\frac{\text{Strength}}{\text{ρ}}$

Unit of melting temperature is N.m/kg