Engineering components and systems

The numbers 152.47 and 3.9 have five and two significant digits, respectively. When we add these two numbers, the calculator will display 156.37 however, since the first column after the decimal point is common to these numbers, the result should be recorded as 156.3. 

Multiplication and Division Rules When multiplying or dividing numbers, the result of the calculation should be recorded with the least number of significant digits given by any of the numbers used in the calculation. For example, 

In the above example, the number 152.47 has five significant digits and the number 3.9 has two significant digits. Therefore, the result of the calculations should be recorded with two significant di ts, because the number 3-9 used in the calculations has the least significant di ts. 

Finally, it is worth noting that in many engineering calculations it may be sufficient to record the results of a calculation to a fewer number of significant digits than obudned following the rules esplained previously. In this book, we present the results of example problems with two or three dedmal poin . 

Every ei meered product is made of components. Let us start with a simple example to demonstrate what we mean by an engineering system and its components. Most of us own a winter coat, which can be looked at as a system. First, the coat serves a purpose. Its primary fimc-don is to offer addidonal insuladon for our bodies so that our body heat does not escape as quickly and as freely as it would without protective covering. The coat may be divided into smaller components the fabric comprising the main body of the coat, insulating material, a liner, threads, zipper(s), and buttons. Moreover, each component may be further subdivided into smaller components. For example, the main body of the jacket may be divided into sleeves, 

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