Density Lab (Melissa Heider)

Title: Sinking Soda Surprise!

Principle(s) Investigated: Density, Buoyancy, Investigation of Nutrition Labels, and Obesity.

Standards : 1.1.N; 1.6.N; 4.1.N; 5.5.G

Materials: Water Tank, Regular Coke (12 oz.), Diet Coke (12 oz.), & Laptops

Procedure: 1. Students first analyze both nutrition labels (coke and diet coke), noting the differences and similarities.

2. Teacher shows students how to log onto socrative for lab "quiz" where students will submit their pre-lab research and hypothesis prior to the experiment. Which soda do you think will float? Which do you think will sink?

3. Teacher performs demo by placing both 12 oz. soda cans into the tank of water

4. Students submit observations to Socrative

5. Both the students and teacher further investigate obesity trends in the U.S. through the CDC.

Student prior knowledge: six major nutrients, classifying nutrients as "dense," creating a balanced diet, & managing body weight.

Explanation: This experiment has two applications. It can apply to physics to explain buoyancy and density, but it also has great health applications.

If the two cans were to be weighed on a scale, we would find that the regular coke weighs more than the diet coke, however they both have the same volume (12 oz, 355mL). This demonstrates the difference between mass and volume. Volume refers to how much space an object occupies, while mass is how much stuff is squeezed inside of that space. In this case, it is evident just from the nutritional label that the regular coke has a lot more "stuff" inside of the same 12 oz. can as the diet coke. The regular coke has 44 grams, or 18 packets, of sugar and 140 calories! Meanwhile the diet coke has 0g of sugar and 0 calories. Diet coke is sweetened with only 180 mg of aspartame (which has it's own health implications).

This leads to a discussion about how sodas are empty calories. After researching obesity trends in the U.S., as well as portion sizes, students will hopefully draw the conclusion that regular sodas are a contributing factor to the obesity epidemic.

It is important to note that sodas like coke have other health implications in addition to obesity such as the deterioration of teeth enamel, osteoporosis, and diabetes. Also inform students that aspartame in coke has been related to dizziness, headaches, and addiction. Rumors about aspartame causing cancer or tumors have been around for years, but lab studies have been inconclusive.

Questions & Answers:

1. Even though the regular coke and the diet coke have the same volume (355mL), why does the regular coke sink?

A: The regular coke sinks because it has greater mass. In other words, it has more "stuff" in it. In comparison to the diet coke, the regular coke has 140 more calories and 44 more grams of sugar. This makes the can more dense. However, both drinks are considered to be empty calories.

2. What is do you think is the relationship between obesity trends in the U.S. and soda consumption?

A: There is a direct correlation between obesity and soda consumption. Sodas are consumed by a large population of Californians every day. Sodas are also empty calories. These side dishes to meals are simply liquid sugar that gets converted to fat when we over consume and exceed the amount of calories we need daily.

3. Based on your knowledge about nutrition and balanced diets, would you recommend drinking diet coke since it has zero calories and zero grams of sugar?

A: No, I would not recommend consuming diet coke. Soda, even if it is diet, contributes to tooth decay and osteoporosis. Additionally the aspartame in diet coke may cause dizziness and addiction. Additionally, we concluded that soda is considered to be empty calories with no nutritional value.

4. What would happen if you drank a Cola every day? Is it bad to have on one special occasions?

A: If you drank Cola everyday you would most experience serious health side effects including obesity and tooth decay. As you got older you may develop diabetes and osteoporosis. However, if you were to drink one only on special occasions you most likely would not feel these side effects. We have learned that consuming in moderation is key to a healthy lifestyle.

Applications to Everyday Life:

Obviously this links directly to food consumption and how foods are packaged. Diet drinks have less "stuff" in them, making them seem healthier or less dense. However do not be fooled, both coke and diet coke have serious health implications.

This lab may also explain how steel ships float on water. They do so because the weight of the water displaced is equal to the buoyant force.

Photographs: Include a photograph of you or students performing the experiment/demonstration, and a close-up, easy to interpret photograph of the activity --these can be included later.

Videos: