Sweet Drinks floating cans experiment : Fizzics Education


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Sweet Drinks

Follow FizzicsEd 150 Science Experiments:

You will need:

  • 1 regular soda drink 375mL
  • 1 diet soda drink 375mL
  • 1 Tub of water


Sweet Drinks Science Experiment - setup_materials
1 Sweet Drinks Science Experiment - placing diet coke into water

Gently place each can of drink into a tub of water large enough to float the cans. Try not to let the cans touch each other.

2 Sweet Drinks Science Experiment - end result

Which can of drink floats higher? Why?

3 Creating sparks on a Van de Graf generator
4 Teacher showing how to do an experiment outside to a group of kids.

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– Help students learn how science really works

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Why Does This Happen?

Each soft drink has the same volume… i.e. 375mL
However, they each have a different mass… weigh each one if you want!

Density is a measure of mass in volume… i.e. how much stuff is packed into a given space.

Regular soda drink contains a large amount of sugar, making it denser than the diet soda drink. The diet soda floats above the regular soda because it is less dense.

The diet soda most likely contains a small amount of artificial sweetener called Aspartame. Aspartame is 200 times sweeter than sugar so you don’t need much.

Your diet does influence your health.

Whether you eat entirely natural foods or those with partly artificial ingredients, food technologists has played a part in developing those products. In fact, nearly every food you eat has been selectively bred over thousands of years.

Variables to test

More on variables here

  • Hot vs. cold water… does it affect how well the cans sink or float?
  • What happens when you use different soda drinks?
  • If you shake the drinks, does this make a difference?
  • What if you use a liquid other than water to repeat the experiment?
  • What about different volumes of cans? Does using bottles make a difference?

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2 thoughts on “Sweet Drinks

  1. The outcome of this makes total sense. I can even picture the sugary syrup used to make these drinks. Yet, it had me stumped until i read the answer. What a great science brain teaser.

    1. It’s a great science activity! When you try this with different size bottles or cans, you’ll find that the outcome described above is not always the case. To float, the weight of water displaced by the can or bottle needs to be greater than the weight of the can or bottle itself. A follow-up activity for this is the testing sinking or floating using Aluminium foil boats and marbles.

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