Engineering Fundamentals: An Introduction to Engineering, 4th ed.c

6.9 Learning Engineering Fundamental Concepts and Design Variables 151

things within our natural world. Some natural laws are stated in a particular way to keep the math-

ematical expressions describing the observations simple. Often, we resort to experimental work

dealing with specific engineering applications. For example, to understand better the aerodynam-

ics of a car, we place it inside a wind tunnel to measure the drag force acting on the car. We may

represent our experimental findings in the form of a chart or a correlation that can be used for

design purposes over a predetermined range. The main difference between laws and other forms

of experimental findings is that the laws represent the results of a much broader observation of

nature, and almost everything that we know in our physical world obeys these laws. The engi-

neering correlations, on the other hand, apply over a very limited and specific range of variables.

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A note to the students: In Chapters 7 through 12, we will focus on teaching you some of the engi-

neering fundamentals that you will see over and over in some form or other during your college

years. Please try to study these concepts carefully and understand them completely. Unfortunately,

today, many students graduate without a good grasp of these fundamental concepts — concepts

that every engineer, regardless of his or her area of specialization, should know. We will focus on

an innovative way to teach some of the engineering fundamental concepts using fundamental

dimensions. Moreover, we will explain them in a way that could be easily grasped at a freshman level.

As we explained previously, from the observation of our surroundings, we have learned

that we need only a few physical quantities (fundamental dimensions) to describe events and

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