Science Project: Making Quicksand
Have you ever seen a movie where the hero is dashing through the jungle when they step in a bog of quicksand which sucks them down to their untimely death, or what seems their untimely death until they're saved at the last minute? Well, quicksand doesn't actually work like that. Sorry to bust your movie going experience, but quicksand is rarely deeper than a few feet and if you hold yourself still you will float to its surface and be free. Try this experiment to see exactly how quicksand works!
Quicksand is called a non-Newtonian fluid, which means that is can be both a solid or a liquid. It depends on the amount of pressure applied to the substance. The molecules that make up quicksand are normally loosely arranged, which makes it behave like a liquid. But when pressure is applied the molecules become ordered and the substance behaves like a solid.
Quicksand is made up of sand (a granular material), clay and water. The sand is so saturated with water that the friction between sand particles if reduced. Which means that it can no longer support weight, like, for example, a person walking over it, which is why you get "sucked" into it. But if you don't move, meaning don't apply pressure to the substance, the quicksand will behave like a liquid and you will float up to the top. The best way to understand quicksand is to make some yourself!
- 1 cup water
- 2 cups cornstarch (cornstarch mimics the granular consistency of sand)
- a place that can get messy
- Slowly add the cornstarch to the water in the bowl and stir.
- Notice how the slower the motion the more fluid the substance.
- Quickly stir the cornstarch and water mixture.
- Notice how the faster motion creates a more solid substance. It might feel like you're "breaking" the cornstarch and water mixture.
- Play with your quicksand!
Yep, it's as easy as that. Maybe not as death defying as in the movies, but definitely pretty interesting!
Have Your Say
Have you ever been scared of quicksand? Now that you know some more about it, does it still freak you out? Tell us about it in the comments section below!