# 1.3 Unit Conversion - University Physics Volume 1 _ OpenStax.pdf

• 4

This preview shows page 1 - 2 out of 4 pages.

5/21/20201.3 Unit Conversion - University Physics Volume 1 | OpenStax1/4Learning ObjectivesBy the end of this section, you will be able to:Use conversion factors to express the value of a given quantity in different units.It is often necessary to convert from one unit to another. For example, if you are reading a European cookbook, some quantities may be expressedin units of liters and you need to convert them to cups. Or perhaps you are reading walking directions from one location to another and you areinterested in how many miles you will be walking. In this case, you may need to convert units of feet or meters to miles.Let’s consider a simple example of how to convert units. Suppose we want to convert 80 m to kilometers. The first thing to do is to list the unitsyou have and the units to which you want to convert. In this case, we have units inmetersand we want to convert tokilometers. Next, we need todetermine a conversion factor relating meters to kilometers. Aconversion factoris a ratio that expresses how many of one unit are equal toanother unit. For example, there are 12 in. in 1 ft, 1609 m in 1 mi, 100 cm in 1 m, 60 s in 1 min, and so on. Refer toAppendix Bfor a morecomplete list of conversion factors. In this case, we know that there are 1000 m in 1 km. Now we can set up our unit conversion. We write theunits we have and then multiply them by the conversion factor so the units cancel out, as shown:Note that the unwanted meter unit cancels, leaving only the desired kilometer unit. You can use this method to convert between any type of unit.Now, the conversion of 80 m to kilometers is simply the use of a metric prefix, as we saw in the preceding section, so we can get the same answerjust as easily by noting thatsince “kilo-” means 10(seeTable 1.2) and

Course Hero member to access this document

Course Hero member to access this document

End of preview. Want to read all 4 pages?

Course Hero member to access this document

Term
Fall
Professor
N/A
Tags
International System of Units, SI prefix, Orders of magnitude, Conversion of units, Metre
• • • 