English units of measurement

Wall Assembly Construction. Because the materials and the design of the assemblies were specified in English units of measurement (for example 2 by 4 lumber, 24 in. on center), dimensions are expressed in English units with SI equivalents. By contrast, our equipment is calibrated in SI units, and consequently SI units are used in the remaining sections of this paper. 

You ve decided to go to Europe and you want to be sure that you order the right size beverage, know how far you ll be traveling by car, and dress appropriately for the weather on any particular day. All these functions relate to changing from English units of measure to metric measure. Here are some of the more useful conversion equivalences you ll need for your travels. For help with the temperatures, refer to Chapter 10 for conversions from Celsius to Fahrenheit and back again. 

Reports on the thermochemistry of propints are numerous but widely scattered. The distinction between gun propints and rocket propints must here be kept in mind. The use of the English units of measurement is still firmly entrenched, but as the impact of a change to the SI system on the numerical values will be slight, this change is to be expected soon... 

The metric system is a decimal-based system in contrast to the English system. In the metric system, mass is represented as the gram, length as the meter, and volume as the liter. Any subunit or multiple unit contains one of these units preceded by a prefix indicating the power of ten by which the base unit is to be multiplied to form the subunit or multiple unit. Scientists favor this system over the not-so-systematic English units of measurement. 

In the United States of America, English units of measurement are still in common use. The inch (in) has been redefined to equal exactly 0.0254 m. The foot (ft) is 12 inches and the mile (mi) is 5280 feet. The pound (lb) is equal to 0.4536 kg (not an exact definition good to four significant digits). 

Perm An English unit of measurement of permeability of material in terms of the permeability coefficient. It is equal to the volume of penetrant in cubic feet that penetrates an area of one square foot of a barrier wall one foot thick per day at a pressure differential of one pound-force per square inch. 

Engineers must be able to use both English units of measure and the metric system. In nanotechnology, engineers... 

The density of a substance is its weight per unit of volume. The unit of volume in the English system of measurement is 1 cubic foot or 1 f. To find the density of a substance, you must know its weight and volume. You then divide its weight by its volume to find the weight per unit volume. 

Meter a unit of measurement of length in the metric system. One meter equals approximately 39.37 inches in the English system. 

Write the units In 1999, the 125 million Mars Climate Orbiter spacecraft was lost when it entered the Martian atmosphere 100 km lower than planned. The navigation error would have been avoided if people had labeled their units of measurement. Engineers who built the spacecraft calculated thrust in the English unit, pounds of force. Jet Propulsion Laboratory engineers thought they were receiving the information in the metric unit, newtons. Nobody caught the error. 

It is important to know that all the questions are based on real numbers. In terms of measurement, units of measure are used from both the English and metric systems. Although conversion will be given between English and metric systems when needed, simple conversions will not be given. (Examples of simple conversions are minutes to hours or centimeters to millimeters.)... 

Chemistry and physics are experimental sciences, based on measurements. Our characterization of molecules (and of everything else in the universe) rests on observable physical quantities, expressed in units that ideally would be precise, convenient and reproducible. These three requirements have always produced trade-offs. For example, the English unit of length inch was defined to be the length of three barleycorns laid end to end—a convenient and somewhat reproducible standard for an agricultural society. When the metric system was developed in the 1790s, the meter was defined to be... 

Uniformity requires that all people use the same measurement system (i.e., metric vs. English) and that all users intend that a given unit of measurement represents the same amount and is based on the same measurement standard used... 

The common unit of measurement for natural gas is the standard cubic foot in the English system and the standard cubic meter in the metric system. Each of these standards is expressed at pressures and temperatures commonly used as standard to the system in the geographical area of concern. In the United States, where standards frequently vary from state to state, the cubic foot is frequently expressed in the English system at standard conditions of 14.73 pounds per square inch absolute (psia) and 60 degrees Fahrenheit (60°F), although there are a number... 

Another common unit of measurement for natural gas is by use of its heating value, expressed in British thermal units (BTU) per standard cubic foot in the English system, and in Joules (or calories) per unit volume in the metric system. Commercially used natural gas, after processing, yields the equivalent of about 950-1050 BTU/ft3. Also used as a unit of measurement is the therm, equivalent to 100,000 BTU, or the nominal heat content of 100 standard cubic feet of lean, processed natural gas. 

The most common unit of measurement in the English system is the mcf or thousand (103) cubic feet. Larger volumes, used to express production or pipeline volumes, are noted as bcf, or billion (109) cubic feet. Even larger volumes, such as reserve figures, usually are expressed as tcf, or trillion (1012) cubic feet. 

Quantitative calculations and qualitative interpretations are fundamental to fully grasp the concepts of chemistry. Quantitative values must include a number and a unit. Two common units of measurement are the conventional (English) system and the metric system. The conventional set of units includes inches, feet, miles, gallons, and pounds. These units, although common in the United States, are not used in science or by most of the world. However, the metric system is becoming more common in the United States. The metric system s base-10 units are easier to use and essential for scientific calculations. However, because most readers of this book are more familiar with the conventional system, it will be necessary to convert to and from the metric system. 

Whenever we measure something, from the weight of a sack of potatoes to the distance to the moon, we must express the result as a number of specific units for example, pounds and miles in the English system of measurement (although even England no longer fully uses that system), or kilograms and kilometers in the metric system. As of 1994, every nation in the world had adopted some aspects of the metric system, with only four exceptions the United States, Brunei, Burma, and Yemen. 

Although scientists rarely use the centuries old English system of measurement, it is still commonly used in the United States to describe quantities in everyday life. Figure... 

The metric system is a system of measurement using units based on the decimal system. Today, in English, it is formally called the International System, abbreviated SI from the original French, Systtme International. The base units of the modern metric system used in general chemistry are given in the following table. From these, you can derive all other units of measure. 

In this chapter and throughout the book, we will use English units for measurements, that is, the load in pounds and the specimen dimensions in inches. Hence, the units of stress and strength (maximum stress) are in pounds per square inch, that is, psi. 

Learn the major units of measure in the English and metric systems, and be able to convert from one system to another. 

The English system is a collection of functionally unrelated units. In the English system of measurement the standard pound (lb) is the basic unit of weight. The fundamental unit of length is the standard yard (yd), and the basic unit of volume is the standard gallon (gal). The English system is used in the United States in business and industry. However, it is not used in scientific work, primarily because it is difficult to convert from one unit to another. Eor example. 

Engineering is about real physical things, which can be measured and described in terms of the units of measure. Most engineering calculations involve these units of measure. It would be simple if there were only one set of such units that the whole world agreed on and used, but that is not the case today. In the United States, most measurements use the English system of units, based on the foot, pound, and degree Fahrenheit, but most of the world uses the metric... 

SLUG - A unit of measure for mass in the English system, which equals 14.6 kg in the SI system. 

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