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Gain knowledge about dimensions, units, and measurements in physics. Learn about fundamental and derived dimensions, units, and systems used in science. Practice dimensional analysis for conversions.
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Quiz • How many significant figures are there in the number 45.07 cm? (5 points) • Four significant figures • Express the operations correctly (5 points each) a. 34.56 cm + 3 cm = b. 34.56 cm X 3 cm = 38 cm 100 cm2
Dimensions, Units, Metric System, Dimensional Analysis Homework: Skim Ch. 1. Complete the handout
I. Dimensions. Physics is a science founded on observation and measurement. Measurements are used to convey information gained about the world around us. Dimensions are measurable physical properties.
Here are a few examples: Length, Time, Mass, Charge, Temperature, Rate, Speed
Dimensions are divided into two types, ____________ and ____________. Fundamental dimensions are just as their name indicates, these are the basic building blocks used to set the framework of measurements.
Dimensions are divided into two types, fundamental and derived. Fundamental dimensions are just as their name indicates, these are the basic building blocks used to set the framework of measurements.
We will use only three basic building blocks for the entire first semester: ______, ____, and ____. Each of these is defined in section one of the text.
We will use only three basic building blocks for the entire first semester: length, mass, and time. Each of these is defined in section one of the text.
Derived dimensions are made of combinations of fundamental dimensions. Here are some examples: area = (length)2,volume = (length)3
II. Units. Units are ____________ values given to the dimensions above. Standardization is necessary; else measurements can easily become meaningless. These are three main systems used today: _____, _____, and the _______ system
II. Units. Units are standardized values given to the dimensions above. Standardization is necessary; else measurements can easily become meaningless. These are three main systems used today: _____, _____, and the _______ system
II. Units. Units are standardized values given to the dimensions above. Standardization is necessary; else measurements can easily become meaningless. These are three main systems used today: m k s, c g s, and the british system
The first two are part of the metric system, a system built off of powers of 10. SI, or mks, is the current standard.
The mks stands for _____, ________, and ______, representing length, mass, and time
The mks stands for meter, kilogram, and second, representing length, mass, and time
The other, older system is cgs, which stands for __________, ____, and ______.
The other, older system is cgs, which stands for centimeter, gram, and second.
Each of the units has the same set of multipliers, allowing each unit to be increased or decreased in amount by factors of ten. These are the multipliers that you must memorize:
The main benefit of the metric system is that it is ______, ___________, and _____________________. Here are some examples of the usage of the prefixes:
The main benefit of the metric system is that it is simple, easy to use, and based on powers of 10. Here are some examples of the usage of the prefixes:
The main benefit of the metric system is that it is simple, easy to use, and based on powers of 10. Here are some examples of the usage of the prefixes: kilogram = 1000 grams millimeter = 0.001 meter decibel = 0.1 bel
III. Dimensional Analysis: Dimensional analysis refers to the process of converting one set of units into another. Here are a few examples:
The conversions between metric and British units are not as easy. The conversions are actually definitions, and are considered exact. Highlight these for memorizing! 1 foot = 12 inches, 1 yard = 3 feet = 36 inches, 1 mile = 5280 feet 1 inch = 2.54 cm, 1 liter = 1000 cc = 1000 cm3, 1 gallon = 4 quarts 1 day = 24 hours, 1 hour = 60 minutes = 3600 seconds 1 micron = 1 micrometer = 1 μm, The density of water = 1.000 g/cm3.
Example #1: How many inches are in 0.00435 mile? Don’t forget proper significant figures!
Example #2: How many firkins can be held in one hogshead? Since all conversions are exact, this is considered an exact computation.