Tuesday, June 24, 2008

Slime - make mine lime

You can make your own cornflour slime to learn about fluids and viscosity.

To do this experiment you will need:

food colouring
a small mixing bowl

What to do:

Pour some cornflour into a mixing bowl.
Stir in small amounts of water until the cornflour has become a very thick paste.
To make the slime the colour of your choice, thoroughly stir about five drops of food colouring into the mixture.
Stir your slime REALLY slowly. This shouldn't be hard to do.
Stir your slime REALLY fast. This should be almost impossible.
Now punch your slime REALLY hard and fast. It should feel like you're punching a solid.
What's happening:

Anything that flows is called a fluid. This means that both gases and liquids are fluids.
Fluids like water which flow easily are said to have low viscosity, whereas fluids like cold honey which do not flow so easily are said to have a high viscosity.
Cornflour slime is a special type of fluid that doesn't follow the usual rules of fluid behaviour. When a pressure is applied to slime, its viscosity increases and the cornflour slime becomes thicker.
At a certain point, slime actually seems to lose its flow and behave like a solid. Cornflour slime is an example of a sheer-thickening fluid.

Make two columns in a book and call one "Low Viscosity" and the other "High Viscosity". Which column do these liquids go into:

honey, molasses, water, Dr Pepper, whipped cream, jam, ketchup, milk, yoghurt, juice, tea.


Weird Science Kids said...

Nice slime recipe! We did it and learned about non-newtonian fluids, polymers, and chains of molecules. Pretty cool. Found some other neat experiments like this slime one on weird science kids. I will put the link for anyone interested.