Lesson 5 Displacement vs. Distance
Creating Graphs in Physics
Why do we use graphs to show an object’s motion?
C5.9 Graph paper and pencil
Graphing is an easy and visual way to show the relationship between two variables. In Unit A of this course, you reviewed manipulated and responding variables. These are the variables whose information are presented in data tables and graphs.
Graphs are useful because they can present a lot of information into one single picture. When you collect data, you sometimes don’t know the relationship between the different variables that are being measured. A graph can give you an idea about how these variables change compared to one another.
Graphs are useful because they can present a lot of information into one single picture. When you collect data, you sometimes don’t know the relationship between the different variables that are being measured. A graph can give you an idea about how these variables change compared to one another.
Watch This
Working with Data © ADLC https://adlc.wistia.com/medias/rajbs9ceky
This video provides you with a great overview of how to collect information during a science experiment, variables in an experiment, and then how to use the data collected to create graphs. It then discusses how graphs can be used to determine
What makes a good graph?
Let’s look at an example and use it to go over all the components of creating a good graph.
A child rides a bicycle on a flat road for 60 s, and the position of the child and her bike are, relative to her initial position, is measured every 10 s. The data table presents the information collected.
| Time (s) |
Position (m) |
|---|---|
| 0.0 |
0.00 |
| 10 |
5.00 |
| 20 |
10.00 |
| 30 |
15.00 |
| 40 |
20.00 |
| 50 |
25.00 |
| 60 |
30.00 |
The manipulated variable is plotted on the x-axis, and the responding variable is plotted on the y-axis. Correct labels, with units, must be included.
In the example, the manipulated variable is time (s) and the responding variable is position (m).
Note: You learned about manipulated and responding variables in Unit A. If you need to review what these variables are, click here. https://adlc.wistia.com/medias/rajbs9ceky
In the example, the manipulated variable is time (s) and the responding variable is position (m).
Note: You learned about manipulated and responding variables in Unit A. If you need to review what these variables are, click here. https://adlc.wistia.com/medias/rajbs9ceky
C5.10 Step 1: label axis
Each axis must be clearly marked with a scale.
To create a good scale,
In the example, time (s) is on the x-axis. The largest value is 60 s, and smallest value is 0.0 s. The scale must be spread out from 0 to 60.
Position (m) is on the y-axis. The largest value is 30.0 m, and the smallest value is 0.00 m. The scale must be spread out from 0.00 to 30.0.
To create a good scale,
- look at the smallest and largest values for the variable
- spread out the scale values so that at least half of the graph paper is used
- the scale does not have to start at 0 unless there is a value of 0 in the data collected
- each box on the graph paper must represent the same amount as the next box
In the example, time (s) is on the x-axis. The largest value is 60 s, and smallest value is 0.0 s. The scale must be spread out from 0 to 60.
Position (m) is on the y-axis. The largest value is 30.0 m, and the smallest value is 0.00 m. The scale must be spread out from 0.00 to 30.0.
C5.11 Step 2: scale for x-axis and y-axis
Each piece of data in the table is plotted in the correct position on the graph.
In the example, seven data points will be plotted on the graph.
In the example, seven data points will be plotted on the graph.
C5.12 Step 3: plot data points
A line of best fit may be drawn for linear graphs. A linear graph is a graph where the data points appear to follow a direct straight path. It is important to know that a line of best fit does not have to touch all the dots.
It should show the general trend of the data, not the exact path the data points follows.
For non-linear graphs, you many need to connect the plotted points to show the trend of the data. A non-linear graph is a graph where the data appear to follow a direct curved path.
In the example, the data points appear to follow a straight path.
For non-linear graphs, you many need to connect the plotted points to show the trend of the data. A non-linear graph is a graph where the data appear to follow a direct curved path.
In the example, the data points appear to follow a straight path.
C5.13 Step 4: line of best fit
The graph is given a title that describes the information presented in the data.
In the example, the data represents the position of the child and her bike, relative to her initial position, every 10 s for 60 s.
In the example, the data represents the position of the child and her bike, relative to her initial position, every 10 s for 60 s.
C5.14 Step 5: title
Read This
Please read pages 473 and 474 in your Science 10 textbook. Make sure you take notes on your readings to study from later. You should focus on how to step-by-step, correctly
create a scatterplot graph step by step and drawing a line of best fit. Remember, if you have any questions, or do not understand something, ask your teacher! Practice Questions
Complete the following practice questions to check your understanding of the concept you just learned. Make sure you write complete answers to the practice
questions in your notes. After you have checked your answers, make corrections to your responses (where necessary) to study from.- In your own words, describe the five steps of creating a graph in science.
Your answer should be a variation of the following.
- Plot the manipulated variable is on the x-axis and the responding variable on the y-axis. Correct labels, with units, must be included.
- Each axis must be clearly marked with a correct scale.
- Each piece of data is plotted in the correct position on the graph.
- Draw a line of best fit (for linear graphs), or connect the plotted points to show the trend of the data (for non-linear graphs).
- Give a title to the graph that describes the information presented in the data.