Research question: How can we measure the affect of light on the rate of photosynthesis? For my design my independent variable I will change the distance between the plant and the light. I will repeat my experiment 5 times. Each time I will move it Cosmic further. This could affect the amount of oxygen bubbles due to the heat coming from the light bulb. My dependent variable will be that every time I start I will keep the light on for 5 min. En I will measure the amount of bubbles have come up. Using deferent light distances might affect the amount of time it takes for the bubbling to take place. Hypothesis: If the change of light distance does affect the amount of time for the bubbles to start then we will see that the affect on the rate of photosynthesis can me measured using different light energies. I will use 5 different light distances. For each light distance I hope to see a different result in the water. I will keep the water level the same each round through to make sure my experiment is accurate.
Variables: Independent variables- I will use a different light distance every round through, I will move It back Cosmic each time. The start position will be CM away from the plant. Dependent variable- I will set a timer for 5 ml. Then I will look at the water and see the amount of bubbles there are. It might take less or more time depending on the strength of the light. Constant variable- for each round through I will keep the water level the same. Doing this will mean I get an accurate answer and depending on the light to start it data collected will be inaccurate.
Aspect 2: Controlling variables: To make sure all the variables stay controlled I will use equipment from the lab to help me. To control my measurements I will use a measuring cylinder, which I will fill up to, the same level with water each time. For my independent variable I will be measuring the distance from the plant to the lamp so I know that the distance is accurate. For my dependent variable I will use a stopwatch this will help me track when min have finished for each test and will give me an accurate measure for each test.
When it comes to collecting my data I will keep an organized table in my book here I can note down any specific time measurements or light measurements and can make notes of any comment worthy occurrences throughout the experiment. Aspect 3: Developing a method for collecting data: Apparatus: Measuring cylinder Stopwatch mall beaker water Plant Water IV Light Paper clip Stand Clamp Potassium hydrogen carbonate Methods to collect sufficient and relevant data: 1. Prepare apparatus 2. Pour an exact amount of water into the mall beaker 3. Place the paperclip on the plant to keep the plant under the water 4.
Place the plant in the water 5. Prepare the light correctly in order for it to shine on the plant and water 6. Start timer 7. Wait for the bubbles to start appearing 8. Stop time 9. Collect data test will take 5 min. Writing down measurements and setting it up correctly will take up to 3 min in between every round.