The Science of Non-Newtonian Fluids
Secondary | Materials | Views: 1977
Note: Although this experiment is not dangerous, it can get messy! Perhaps you could protect the area if you are working indoors, or give it a try outside! Wear an apron or old clothers, and something to protect your eyes. Also, work with an adult.
You will Need:
- Cornflour
- Water
- Measuring cups
- Mixing bowl
- Spoon
- Container, like a lunch box, to store your fluid once you have made it.
What to Do:
- Begin by adding 2 cups of cornflour and 2 cups of water to your mixing bowl. Start mixing ad judge its consistency.
- Add more cornflour or water as necessary, so that your mixture is not too think nor too liquidy.
- Mix thoroughly – start off by mixing with a spoon, however after a while you might find it easier to mix with your hands.
- To check that you have the right consistency, tap the surface of your fluid mixture. If it does not splash when you tap it, you have the correct consistency. It will also become much more difficult to mix and move around your hands in the fluid.
What is a non-Newtonian fluid?
Next, you can check the properties of the mixture you have made:
You will Need:
- The container with your mixture
- A container with water
- Another container with honey
- A large spoon (or hammer with adult supervision for more fun!)
What to Do:
- With each liquid, slowly immerse the hammer in the liquid and then do so quickly! How does each liquid behave? What are the similarities/differences? Does each liquid behave like you would expect?
- What happens with the mixture we have made, which is a non-Newtonian fluid? Does it behave in a different way to the other liquids? What is the difference when you put the hammer in the mixture slowly versus quickly?
How does it work?
- When you slowly apply a force to a non-Newtonian fluid, it behaves like a liquid. However, when you quickly apply a force, it acts like a solid and shows resistance!
- Watch the video for some cool footage of how a non-Newtonian fluid behaves!
What about viscosity?
- Viscosity measures the resistance of a liquid (or a gas). Water has a low viscosity, and flows really well, whereas liquids like honey are more viscous and flow more slowly. These are Newtonian fluids – they follow Newton’s Law and can change with temperature.
What about non-Newtonian fluids?
- As we have learned, our cornflour and water mixture changes its viscosity based on force, not temperature, making it different from Newtonian fluids. It does not follow Newton’s Law.
- Watch what happens in the video with ketchup…is it Newtonian, or non-Newtonian?
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