Measurements

Description and Measurement  Key Vocabulary  Precision  Accuracy

Description and Measurement  Precision- how close measurements are to one another  Example: If you measure the width of a floor tile several times and you get: 1.0m, 1.1m, 1.0m, and 1.0m; then your results are precise

Description and Measurement  Accuracy- comparison of a measurement to an accepted value  Example: when an archer shoots and arrow and hits the bullseye, the archer is accurate

Description and Measurement

 Significant Figures- you can only be as precise as your least precise measurement  Digits other than zero (0) are always significant  Zeros after a decimal point are significant  Zeros between any other digit are significant  Initial zeros are not significant  Zeros at the end of a whole number may or may not be significant  Depends on if you place a decimal after the zero

Description and Measurements  How many significant figures in these examples  seconds  meters  350 kilometers  5.00 milliliters  450. grams

Description and Measurements  Significant Figures- multiplication and addition  Multiplication/Division- determine the number of significant figures in each number in the problem, your answer can only have as many significant figures as your number with the least number of digits  Addition/Subtraction- determine the number of the numbers in the problem, the answer is determined by the least precise number in the problem

SI Units  Key Vocabulary  SI  Meter  Volume  Mass  Kilogram  Weight  Kelvin  Rate

SI Units  SI- french term “Systeme International d’Unites” or as known here “International System” or “Metric System”  All measurements are related in multiples of 10  Become very familiar with Tables 1 and 2  These will be with you for the rest of your life  You will encounter these units in every science class from now through college, and in your everyday life  The United States is one of only a few countries that has not converted to the metric system

SI Units  Length- SI unit of length is the METER  One meter is about the length of a baseball bat  Volume- how much space something takes up  SI unit of volume is the cubic meter (m³)  Also measured in cubic centimeters (cm³) which is equivalent to a milliliter (mL)

SI Units  Temperature- how hot or cold and object is  SI unit for temperature is the kelvin (K)  Figure 12 on Pg. 54 shows the relationship between Kelvin, Celsius, and Fahrenheit  Mass- measure of the amount of matter in an object  SI unit of mass is the kilogram (kg)  Weight- measurement of force due to gravity  SI unit of weight is a newton (N)

SI Units  Rate- amount of change in an object over a given time  SI unit for time is the second (s)

Drawings, Tables, and Graphs  Key Vocabulary  Table  Graph  Line Graph  Bar Graph  Circle Graph

Drawings Tables and Graphs  Table- information organized into rows and columns to better display data  Graph- plotted data from a table  3 types of graphs  Line graph  Bar graph  Circle graph

Drawings Tables and Graphs  Line Graph- shows the relationship between two variables through plotted points and a connected line

Drawings Tables and Graphs  Bar Graph- shows relationships among many variables through rectangular blocks or bars

Drawings Tables and Graphs  Circle Graph- split up to show the parts that make up a whole

Drawings Tables and Graphs  Graphing Rules  X axis or horizontal axis is always the independent variable  Y axis or vertical axis is the dependent variable  All graphs must have:  Title  Legend  Labeled Axis  Units