A physical quantity is a quantity that can be used in the mathematical equations of science and technology.Examples are the mass of the moon and the electric charge of the proton. A quantity in the particular sense is a quantifiable or assignable property ascribed to a particular phenomenon, body, or substance.National Type Evaluation Program (NTEP)Ī quantity in the general sense is a property ascribed to phenomena, bodies, or substances that can be quantified for, or assigned to, a particular phenomenon, body, or substance.National Conference on Weights and Measures (NCWM).External Resources for Weights and Measures Expand or Collapse.Fuels and Lubricants Subcommittee (FALS).National Legal Metrology Expand or Collapse.Laboratory Metrology Expand or Collapse.International Legal Metrology Expand or Collapse.OWM Products and Services Expand or Collapse.Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License. We recommend using aĪuthors: William Moebs, Samuel J. Use the information below to generate a citation. Then you must include on every digital page view the following attribution: If you are redistributing all or part of this book in a digital format, Then you must include on every physical page the following attribution: If you are redistributing all or part of this book in a print format, Want to cite, share, or modify this book? This book uses the This failure to pay attention to unit conversions cost hundreds of millions of dollars, not to mention all the time invested by the scientists and engineers who worked on the project. This error caused the probe to follow a very different trajectory from what NASA thought it was following, which most likely caused the probe either to burn up in the Martian atmosphere or to shoot out into space.
#Si unit conversion chart software
However, other pieces of software that used these values for course corrections expected them to be recorded in the SI units of newton-seconds (N-s), as dictated in the software interface protocols. Subsequent investigations showed a piece of software called SM_FORCES (or “small forces”) was recording thruster performance data in the English units of pound-seconds (lb-s). On September 23, 1999, while attempting to guide the probe into its planned orbit around Mars, NASA lost contact with it. This probe was launched by NASA on December 11, 1998. One famous example of this situation was seen with the Mars Climate Orbiter. Unit conversions may not seem very interesting, but not doing them can be costly. You should get the same answer both ways.) What is that in square kilometers (that is, km 2)? (Try doing this both by converting 10 7 m to km and then squaring it and then by converting 10 14 m 2 directly to square kilometers. We know from Figure 1.4 that the diameter of Earth is on the order of 10 7 m, so the order of magnitude of its surface area is 10 14 m 2. We write the units we have and then multiply them by the conversion factor so the units cancel out, as shown: In this case, we know that there are 1000 m in 1 km. Refer to Appendix B for a more complete list of conversion factors. in 1 ft, 1609 m in 1 mi, 100 cm in 1 m, 60 s in 1 min, and so on. A conversion factor is a ratio that expresses how many of one unit are equal to another unit. Next, we need to determine a conversion factor relating meters to kilometers.
In this case, we have units in meters and we want to convert to kilometers. The first thing to do is to list the units you have and the units to which you want to convert. Suppose we want to convert 80 m to kilometers.
#Si unit conversion chart how to
Let’s consider a simple example of how to convert units. In this case, you may need to convert units of feet or meters to miles. Or perhaps you are reading walking directions from one location to another and you are interested in how many miles you will be walking. For example, if you are reading a European cookbook, some quantities may be expressed in units of liters and you need to convert them to cups. It is often necessary to convert from one unit to another. Use conversion factors to express the value of a given quantity in different units.By the end of this section, you will be able to:
0 kommentar(er)
