Physical Science Mr. Barry Graphing in Science Physical Science Mr. Barry

Using Graphs Graph: a visual display of information or data Shows Change! Graphs show how two or more items change in relation to each other What is an example of two things that you could make a graph with?

Features of a Graph Title: each graph must have a title or it is meaningless Labels: each axis must be labeled and have a unit Axes: x and y axes represent the change in different variables Variable: a quantity subject to change Independent: changed during experiment or observation (ALWAYS on x-axis) Dependent: changes as a result of change in the independent variable (ALWAYS on y-axis)

Example What is the title? What does the x-axis represent? The y-axis? What is the independent variable? What is the dependent variable? What can we conclude from looking at this graph?

Types of Graphs Bar Graphs: compares information gathered by counting Ex: number of students in this class of a certain age Circle Graphs (Pie Graph): shows how a whole can be broken down into parts (percentages) Ex: percent of students in the school that are in certain science classes

Types of Graphs Line Graphs: shows a relationship where one variable (dependent) changes as a result of another variable (independent) This is the type of graph most helpful for science More than one relationship can be shown on a line graph

Making a Line Graph 1. Put all of your information into a chart with columns for the independent variable and the dependent variables 2. Find the largest value in each column. Increase that value to an easily divisible number 3. Make increments on each axis equal to parts of the easily divisible number 4. Plot each point in the chart. Connect each plotted point 5. Done!

Example Jack’s little brother Jim is just learning to walk. He walks 1 m in 6 s, 2 m in 13 s, 3 m in 19 s and 3.5 m in 27 s. He needs to graph this information for a class at school. Help him out! Independent Dependent Variable Variable

Example Title: y-axis: (0,0) x-axis: