Activity Overview
In this activity, students examine quantities that are linearly related and can be visually represented using a straight-line graph. Students collect distance versus time data using a motion detector and find a model for the time-distance data set.
Before the Activity
Connect the computer to the CBL 2™ using the TI connectivity cable
Connect CBR 2™ to the DIG/SONIC port of the CBL 2™ unit and set it up to take readings
Open a new TI InterActive!™ document
See the attached PDF file for detailed instructions for this activity
Print pages 8 - 13 from the attached PDF file for your class
If you plan to use the EDC quiz as a follow-up, download the file and have it ready to distribute to students via TI-Navigator™.
During the Activity
Distribute the pages to the class.
Follow the Activity procedures:
Place the motion detector on the table and collect distance versus time data as the student walks away from the unit
Plot a graph of distance versus time
Observe that the graph is linear
Find b (y-intercept) when x = 0 on the graph
Find the slope of the line by guess-and-check method until the slope value models the data well
Use values of b and m to form a linear equation of the line in the y = mx + b form
Identify two points and calculate the slope using the formula m = (y2 - y1)/(x2 - x1)
Compare the slope found earlier with the guess-and-check method and the calculated method
Use the linear regression function to get a line that best fits the data and record the linear equation y = ax + b and values of a and b
Compare the values of the slope and y-intercept from the linear regression model with the values found experimentally
Observe that the linear regression equation is a better fit
After the Activity
Students complete the analysis and answer questions.
If you are using the TI-Navigator System with the TI-73 you will need the attached .pdf file.
Review student results:
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary