Education Technology

# Activities

• ##### Subject Area

• Math: Algebra I: Exponential Functions
• Math: PreAlgebra: Nonlinear Functions
• Science: Earth Science: Earth's Surface

6-8

45 Minutes

• ##### Device
• TI-73 Explorer™
• TI-Navigator™

TI Connect™

• ##### Accessories

CBL™/CBL 2™
Sensor - Light
TI Connectivity Cable

• ##### Other Materials
This is Adventure 8 from the EXPLORATIONS Book:
Adventures in Data Collection with TI-73 Explorer™.

The following materials are required for this activity:
• Light sensor
• Clear 1000 ml container
• 50 g of dirt
• Spoon or scoop
• Stirrer
• Flashlight

## Muddy Water - Adventure 8

#### Activity Overview

Students use a light sensor to analyze the effect of storm water run-off on the turbidity of local water. They interpret and analyze scatter plots and understand exponential relationship.

#### Before the Activity

• Connect CBL 2™ to the calculator.
• Plug light sensor into channel 1 of the CBL 2
• Launch the DataMate program
• See the attached PDF file for detailed instructions for this activity
• Print pages 52 - 53 from the attached PDF file for your class
• Transfer files to student calculators using TI-Navigator™  "send to class" feature
• #### During the Activity

Distribute the pages to your class.

Collect Data:

• Align the flashlight, container of water, and the CBL 2 light sensor so that the light passes through the container of water directly into the light meter
• Put 10 g of dirt in the water and stir
• Note the amount of light transmitted to the light meter
• Repeat the steps until 50 g of dirt have been added to the water
• Record the light reading for each test
• Graph the data as a scatter plot
• Trace the points on the plot and explore graphs of exponential functions
• Understand how water clarity decreases the most with the initial-run off
• #### After the Activity

Students analyze the results and answer the questions in the worksheet

Review student results:

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