Major Points*A quantitive observation is called a measurement and always consists of a number and a unit
*We can conveniently express very large or very small numbers using scientific notation, which represents the number as a number between 1 and 10 multiplied by 10 raised to a power. *Units give a scale on which to represent the results of a measurement. The 3 systems discussed are the English, metric, and SI systems. The metric and SI systems use prefixes to change the size of the units. *The mass of an object represents the quantity of matter in that object. *All measurements have a degree of uncertainty, which is reflected in the number of significant figures used to express them. Various rules are used to round off to the correct number of significant figures in a calculated result. *We can convert from one system of units to another by a method called dimensional analysis, in which conversion factors are used. *Temperature can be measured on 3 different scales: Fahrenheit, Celsius, and Kelvin. We can readily convert among these scales. *Density is the amount of matter present in a given volume (mass per volume). Density=mass/volume. ActivitiesOnline ResourcesDensity:
http://cnx.org/content/m42187/latest/ Scientific Notation and Significant Figures: http://cnx.org/content/m37445/latest/ Conversions: http://cnx.org/content/m40840/latest/ VideosMultiplying/Dividing Significant Figures:
http://watchknowlearn.org/Video.aspx?VideoID=45920 Adding/Subtracting Significant Figures: http://watchknowlearn.org/Video.aspx?VideoID=45919&CategoryID=14275 |
Example Calculations |