Chapter 1, Problem 1.79P

Interpretation Introduction

Interpretation:

The cross-sectional areas of wires of aluminum and of steel number 5137 are to be calculated.

Concept introduction:

Meter square $\left({\text{m}}^{\text{2}}\right)$ is the SI unit of the area. The English equivalent of the area is miles square $\left({\text{mi}}^{\text{2}}\right)$. The conversion factor to convert the area from ${\text{mi}}^{\text{2}}$ to ${\text{ft}}^2$ is,

  ${\left(0.3048\right)}^2{\text{ m}}^2=1{\text{ ft}}^2$

The conversion of one unit into another can be done using a proper conversion factor. Conversion factors are the ratios that relate the two different units of a quantity. It is also known as dimensional analysis or factor label method.

In the unit conversion problems, the given information is multiplied by the conversion factors to obtain the desired information. The unit conversion can be done as follows:

  $\left(\cancel{\text{beginning unit}}\right)\left(\frac{\text{Final unit}}{\cancel{\text{beginning unit}}}\right)=\text{Final unit}$