Section 5: Graphs in Science What type of data can line graphs display? How do you determine a line...
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Section 5: Graphs in Science What type of data can line graphs display? How do you determine a line of best fit or the slope of a graph? Why are line graphs powerful tools in science? Chapter 1 Introduction to Physical Science
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Transcript of Section 5: Graphs in Science What type of data can line graphs display? How do you determine a line...
Section 5:Graphs in Science
What type of data can line graphs display?
How do you determine a line of best fit or the slope of a graph?
Why are line graphs powerful tools in science?
Chapter 1 Introduction to Physical Science
Why use Graphs? Because of their visual nature, graphs can reveal patterns or
trends that words and data tables cannot.
Scientists commonly use bar graphs, circle graphs, and line graphs.
The Importance of Graphs Line graphs are used to
display data to show how one variable changes in response to another variable. In this experiment, the responding variable is the time it takes for the water to boil. The manipulated variable is the volume of water in the pot.
Chapter 1 Introduction to Physical Science
Open your textbooks to page 37, and let’s look at the steps of plotting a line graph.①Draw the axes②Label the axes③Create a scale④Plot the data⑤Draw a line of best fit⑥Add a title
(horizontal axis = x-axis = independent variable, vertical axis = y-axis = dependent variable)
(focus on general pattern, not connecting dots)
(include both independent and dependent variables)
Why Draw a Line of Best Fit? A line of best fit emphasizes the overall trend
shown by all the data taken as a whole.
Chapter 1 Introduction to Physical Science
Slope:The steepness of the graph line
Slope = Rise = y2 - y1 Run x2 - x1
Pick any two points on the line to use the formula to find the slope of the line.
Slope The slope of a graph
line tells you how much y changes for every change in x.
Chapter 1 Introduction to Physical Science
Slope = 25 km – 10 km = 15 km = 0.5 km/min50 min – 20 min 30 min
Using Graphs to Identify Trends
Line graphs are powerful tools in science because they allow you to identify trends and make predictions.
This graph’s data forms a straight line, so it is linear
Chapter 1 Introduction to Physical Science
Using Graphs to Identify Trends
Chapter 1 Introduction to Physical Science
Not all line graphs will have data that fall on a straight line.
This graph is nonlinear
Here are some more nonlinear graphs:
No trend
Chapter 1 Introduction to Physical Science
Even nonlinear graphs with no recognizable pattern provides useful information to scientists….
It most likely means that there is no relationship between the two variables.
