See Thru Water
Teacher Page
Problem:To simulate the light levels in water
Question: How much light can pass through a body of water?
Materials:
Graphing calculator loaded with the PHYSCI program
CBL
Light probe
Light source
Mirrors
Clear container of water (aquarium, clear plastic shoe box)
Ocean salt (from pet store)
Dirt or sand
Beginning the lesson:
Pose the question, “How much light can pass through a body of water?”
Students may question the depth, type of water, pollutants, etc. Lead a discussion in this.
Have student generate experimental questions based on the class discussion.
Examples:
Does fresh water allow more light to pass through than salt water?
Does the temperature of the water make a difference?
How does soil from runoff affect light transmission?
Does the depth of the water make a difference?
CBL / Graphing calculator Procedure:
- Prepare the graphing calculator and CBL:
Plug the light probe in channel 1 (CH1) of the CBL unit.
Use the link cable to connect the calculator to the CBL unit. Plug the cable into the bottom of both the calculator and the CBL.
Turn the calculator on.
Turn the CBL on. The CBL must be on as you are setting up the calculator.
Press the PRGM key on the calculator.
Select 1:PHYSCI.
Press. ENTER
Press ENTER until you come to ***MAIN MENU***
Select 1:SET UP PROBES
Enter 1 after ENTER NUMBER OF PROBES. Press ENTER.
Select 4:LIGHT
Enter 1 after ENTER CHANNEL NUMBER. Press ENTER.
Back at the ***MAIN MENU*** Select 2:COLLECT DATA
If you want to collect discrete, individual data points:
At the DATA COLLECTION menu, select 4:TRIGGER
Place the light sensor at the spot where you wish to collect data.
Press TRIGGER on the CBL. The light intensity at that point is stored.
The calculator screen will read:
TRIGGER
1:MORE DATA – choose this to take multiple readings; this can be continued as long as needed
2:STOP – choose this if one reading is sufficient; select 4:VIEW DATA, the light intensity will be stored in List 2.
3:PAUSE – skip this
If you want to collect continuos data over a period of time:
At the DATA COLLECTION menu, select 2:TIME GRAPH
Enter how often the samples will be taken in seconds. Press ENTER.
Enter the number of samples to be taken. Press ENTER.
The sample time, number of samples and length of the experiment in seconds will be shown on the calculator. Press ENTER.
Select 1:USE TIME SETUP.
Place the probe where you wish to collect data. Press ENTER on the calculator to begin sampling.
Data will be stored in the calculator as Time in List 1 and Light Intensity in List 2.
Press ENTER to see the graph.
To repeat the data collection, press ENTER, select 2:yes, otherwise, select 1:NO.
To see your data select 4:VIEW DATA
Have students design an experiment to find the answers to their questions.
Question: Does the amount of salt have an effect on the amount of light that can pass through water?
Materials: Aquarium or large, clear shoe box
Water
Ocean salt
Light source
CBL with light sensor
TI graphing calculator loaded with PHYSCI program
Procedure:
SET UP CBL & CALCULATOR:
Plug the light probe in channel 1 (CH1) of the CBL unit.
Use the link cable to connect the calculator to the CBL unit. Plug the cable into the bottom of both the calculator and the CBL.
Turn the calculator on.
Turn the CBL on. The CBL must be on as you are setting up the calculator.
Press the PRGM key on the calculator.
Select 1:PHYSCI.
Press. ENTER
Press ENTER until you come to ***MAIN MENU***
Select 1:SET UP PROBES
Enter 1 after ENTER NUMBER OF PROBES. Press ENTER.
Select 4:LIGHT
Enter 1 after ENTER CHANNEL NUMBER. Press ENTER.
Back at the ***MAIN MENU*** Select 2:COLLECT DATA
At the DATA COLLECTION menu, select 4:TRIGGER
SET UP EXPERIMENT:
Fill container with fresh water.
Place the light sensor at the spot where you wish to collect data.
Press TRIGGER on the CBL. The light intensity at that point is stored.
Select 1:MORE
Stir one cup of ocean salt into the tank. Mix well.
Place the light sensor in the same spot.
Press TRIGGER on the CBL. The light intensity at that point is stored.
Select 1:MORE
Repeat procedure, adding 1 cup of ocean salt at a time until 5 cups have been mixed in and the light intensity has been measured.
Select 2:STOP
Select 4:VIEW DATA . The light intensity for each sample is stored in List 2.
Data:
Make bar graph of your data.
Conclusions:
Write a paragraph explaining your results.
Question: Does the depth have an effect on the amount of light that can pass through water?
Materials: Aquarium or large, clear shoe box
Water
Ocean salt
Light source (a laser works best)
Mirrors
CBL with light sensor
TI graphing calculator loaded with PHYSCI program
Procedure:
SET UP CBL & CALCULATOR:
Plug the light probe in channel 1 (CH1) of the CBL unit.
Use the link cable to connect the calculator to the CBL unit. Plug the cable into the bottom of both the calculator and the CBL.
Turn the calculator on.
Turn the CBL on. The CBL must be on as you are setting up the calculator.
Press the PRGM key on the calculator.
Select 1:PHYSCI.
Press. ENTER
Press ENTER until you come to ***MAIN MENU***
Select 1:SET UP PROBES
Enter 1 after ENTER NUMBER OF PROBES. Press ENTER.
Select 4:LIGHT
Enter 1 after ENTER CHANNEL NUMBER. Press ENTER.
Back at the ***MAIN MENU*** Select 2:COLLECT DATA
At the DATA COLLECTION menu, select 4:TRIGGER
SET UP EXPERIMENT:
Fill container with fresh water.
Put mirrors on both ends of the container.
Shine the light source through the water without a reflection. This represents Depth 1.
Place the light sensor at the spot where you wish to collect data.
Press TRIGGER on the CBL. The light intensity at that point is stored.
Select 1:MORE
Reflect the light source once. This represents Depth 2.
Place the light sensor in the same spot.
Press TRIGGER on the CBL. The light intensity at that point is stored.
Select 1:MORE
Repeat procedure, reflecting the light as many times as possible to simulate increasing depths.
Measure the light intensity at each depth.
Select 2:STOP
Select 4:VIEW DATA . The light intensity for each sample is stored in List 2.
Data:
Make bar graph of your data.
Conclusions:
Write a paragraph explaining your results.
Question: Does color have an effect on the amount of light that can pass through water?
Materials: Aquarium or large, clear shoe box
Water
Ocean salt
Light source (a laser works best)
Food coloring
CBL with light sensor
TI graphing calculator loaded with PHYSCI program
Procedure:
SET UP CBL & CALCULATOR:
Plug the light probe in channel 1 (CH1) of the CBL unit.
Use the link cable to connect the calculator to the CBL unit. Plug the cable into the bottom of both the calculator and the CBL.
Turn the calculator on.
Turn the CBL on. The CBL must be on as you are setting up the calculator.
Press the PRGM key on the calculator.
Select 1:PHYSCI.
Press. ENTER
Press ENTER until you come to ***MAIN MENU***
Select 1:SET UP PROBES
Enter 1 after ENTER NUMBER OF PROBES. Press ENTER.
Select 4:LIGHT
Enter 1 after ENTER CHANNEL NUMBER. Press ENTER.
Back at the ***MAIN MENU*** Select 2:COLLECT DATA
At the DATA COLLECTION menu, select 4:TRIGGER
SET UP EXPERIMENT:
Fill container with fresh water.
Shine the light source through clear water. Place the light sensor at the spot where you wish to collect data.
Press TRIGGER on the CBL. The light intensity at that point is stored.
Select 1:MORE
Add two drops of food coloring to the water.
Place the light sensor in the same spot.
Press TRIGGER on the CBL. The light intensity at that point is stored.
Select 1:MORE
Repeat procedure, adding two drops of food coloring at a time.
Measure the light intensity each time.
Select 2:STOP
Select 4:VIEW DATA . The light intensity for each sample is stored in List 2.
Data:
Make bar graph of your data.
Conclusions:
Write a paragraph explaining your results.
This activity may address TEKS 8.10 b – describe interactions among solar, weather, and oceans systems; 8.12c – predict the results of modifying the Earth’s nitrogen, water, and carbon cycles; 8.14c –describe how human activities have modified soil, air and water quality