Something to do at home! Cornflour slime ; teach your ‘Junior Einsteins’ about Newtonian & Non-Newtonian Fluids!
one cup of water
Cornflour slime is a ‘stir thickening fluid’ (non-newtonian)– it gets thicker when a force is applied on it. It becomes runny when the force is removed. It is at the same time a liquid and a solid depending on the approach. Water is a Newtonian fluid.
Put cornflour into a large bowl.
Add 2-3 drops of food colouring into the water and add to the cornflour. Mix well.
Ask your children to put their finger into the mix slowly , see how it is so soft and slimy. Then ask children to punch the slime ! They will see it becomes hard. This is because the pieces of cornflour that normally flow easily over each other when little or no force is applied, now the cornflour particles lock together acting like a solid. Such fun, Such mess!
So we made a stir-thickening fluid with cornflour and water but lots of fluids behave differently to this, for example water and honey and some can even be stir thinning fluid, that means they get thinner and thinner the more you stir them. Toothpaste is an example and also Hair gel.
Put some hair gel on your hand and rub hands together. If you kept moving the hair gel in your hands around it stays thin and runny . If you stop moving it, it became thick and goopy and could hold your hair in an absolutely magnificent hairstyle.