Education Technology

# Activities

• ##### Subject Area

• Math: Algebra I: Linear Functions

9-12

60 Minutes

• ##### Device
• TI-73 Explorer™
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition

TI Connect™

• ##### Accessories

CBL™/CBL 2™
CBR™/CBR 2™
Sensor - Dual Range Force
Sensor - Motion Detector
TI Connectivity Cable
Vernier LabPro®

• ##### Other Materials
This is Activity 9 from the EXPLORATIONS Book: Real-World Math Made Easy.

The following materials are required for this activity :
• Ring stand
• One long rubber band

## Stretch It to the Limit: The Linear Force Relation for a Rubber Band

#### Activity Overview

In this activity, students' will use a force sensor and a motion detector to study the relationship between the force applied to a rubber band and the distance to which it stretches. They will then model force versus strech data with a proportional relationship.

#### Before the Activity

• Connect the force sensor to Channel 1 on the CBL 2™ or Vernier LabPro®
• Connect the motion detector to the DIG/SONIC port of the CBL 2 or the DIG/SONIC 1 port of the LabPro
• Connect the CBL 2 or LabPro to the calculator using the Unit-to-Unit cable
• See the attached PDF file for detailed instructions for this activity
• Print pages 81 - 88 from the attached PDF file for your class

#### During the Activity

Distribute the pages to your class.

• Prepare the force sensor and motion detector for data collection
• Stretch and relax the rubber band
• Use the force sensor and measure the force of the pull
• Use the motion detector and record the amount the rubber band is stretched
• Plot graphs of force versus time and distance versus time
• Graph force versus distance
• Plot the line of proportionality with different values for the slope and find the line that provides a good fit for the data
• Calculate the value of the slope from the equation and compare the values
• Do a linear regression on all the data points and determine the regression line equation
• #### After the Activity

Students' will fill in the Student Data Collection and Analysis Sheet and answer the questions listed in it.

Review student results

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