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The density of Coca-ColaFeatured science projectScience project video


This experiment was performed to find out if the different brands of soda can drinks have a higher density or lower density than water. The experiment was done to compare the difference in densities between regular Coke and Diet Coke.


Regular Coke and Diet Coke will both sink in water

Scientific Terms

Density, mass



The density of a substance or matter, is the mass of one unit volume of that matter. For example the density of water is 1gram/cm3.

Density = mass (gram) / volume (cm3)

When an object has a density that is higher than the medium it is placed into, then that object will sink in that medium. Similarly if the density of the medium is higher than the density of the object, the object will float in that medium.

For example, hydrogen has a density of 0.0001g/cm3 compared to air which has a density of 0.0013g/cm3. This is the reason why hydrogen inflated balloons will float in the air.

Similarly, water has a density of 1g/cm3. Copper has a density of 8.9g/cm3 and will immediately sink in water. Wood on the other hand has a density of 0.53g/cm3 only and it will float in  water.

The method to determine the density of an object is to first check the weight of the object with a weighing machine. The next step is to determine its volume. If the shape of the object makes it difficult to measure  its volume,  find a measuring cup or beaker  that is big enough to contain the object. Place the object in the cup and fill it with water. Record the volume of the water in the cup. Remove the object from the water. The difference between the level of the water with the object and without the object is the volume of the object.

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Complexity level:
Project cost ($):
Time required:
1 hour to prepare, 1 hour for experiment
Material availability:
Easily found. May be purchased at a supermarket.
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