What happens when air passes around a cylindrical object like a soda can? Watch the video to the left to learn more about high pressure and low pressure systems. The results might surprise you!

Diet Soda and Regular Soda

Engage

Imagine that you are at a backyard family barbecue on a hot summer day and you are craving a cold can of regular soda. Inside the cooler are a mixture of regular and diet sodas in ice water. Without looking and using only your sense of touch, you pull out a can of regular soda.

How is this possible?

Explore

Gather the necessary materials and experiment on your own. Alternatively, watch the video to the left from SICK Science!

Notice...

• The can of regular soda will sink.

• The can of diet soda will float.

Test other varieties and brands. What are similarities and differences in your tests?

Explain

Analyze and interpret the two soda cans. What do you find? Many students will eventually find the nutrition facts o the soda cans.

• Diet soda contains zero sugar.

• Regular soda contains many grams of sugar.

An object's ability to float is based on how dense the object is relative to the water it is in. An object more dense than the water will sink and an object less dense than the water will float. This concept explains why an anchor sinks and a boat floats.

All sealed beverages contain a tiny air pocket from the manufacturing process. That air pocket is enough to cause a can of diet soda to be less dense than the water, causing the can to float. The air pocket also exists in a can of regular soda, but regular soda also contains approximately 40 grams of added sugar. The sugar makes the can of regular soda more dense than the water, causing the can to sink.