# Activities

• • • ##### Subject Area

• Math: Algebra I: Linear Functions

• ##### Author 9-12

90 Minutes

• ##### Device
• TI-83 Plus Family

TI Connect™

• ##### Accessories

CBR™/CBR 2™
TI Connectivity Cable

• ##### Other Materials
This is Activity 2 from the EXPLORATIONS Book:
A Hands-On Look at Algebra Functions: Activities for Transformation Graphing .

## Lines, Models, CBR - Let's Tie Them Together (Electronic Format Only)

#### Activity Overview

In this activity, students use a motion detector to collect "linear" motion data and examine the relationship between a physical action and a mathematical and/or graphic model of that action. The students will use the "eyeball" method to find the mathematical model.

#### Before the Activity

Install the Transformation Graphing application on the students' graphing calculators using one of these two methods:

• TI Connect™,  a TI Connectivity Cable, and the Unit-to-Unit Link Cable
• TI-Navigator™  "send to class" feature
• Connect the CBR 2™ to the calculator using the Unit-to-Unit link cable
• See the attached PDF file for detailed instructions for this activity
• Print pages 11 - 16 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to the class.

• Place the CBR on a table
• Set up the Data Logger App to record one reading every 0.1 second for 6 seconds
• Walk away from the CBR at a constant rate
• Study the distance versus time graph
• Set up an unconnected scatter plot of the data
• Activate the Transformation Graphing application and use the slope-intercept equation to find the values of A and B that will form a line that models the data
• Determine the slope, write the equation of the line which best fits the data
• Understand the slope of the line represents the speed of the walker

• In a second trial, students try to walk and duplicate the model graph
• Use piecewise function to model the data
• In a third trial, students try to walk and match the graph with a negative slope
• In each trial, students identify how the direction and speed of motion affects the distance versus time plot
• #### After the Activity

Students will complete the Student Worksheet and answer questions listed on it.

Review student results:

• As a class, discuss questions that appeared to be more challenging
• Re-teach concepts as necessary