Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: Ideal States of Matter

Learn more physics!

Most recent answer: 10/22/2007
Q:
I am doing a demonstration on non-Newtonian fluids (cornstarch/water mixture) for our Science Fair. I need a simple definiton of "ideal liquids" and "ideal solids". Thank you.
- Anthony (age 8)
Pony Express Christian School, v
A:
Anthony -

Unfortunately, there are no generally accepted definitions for 'ideal liquids' and 'ideal solids.' In most cases, though, we can say that a liquid is something that can flow, and a solid is something that will remain rigid unless you push on it. So something like water is definitely a liquid since it changes its shape by flowing into a container. But ice is definitely a solid since it bends just a tiny bit, without flowing, until it actually breaks.

There are, however, some cases (like the cornstarch/water mixture that you mentioned) that don't quite fall into either category. That's why everyone isn't quite agreed on these definitions.

We've actually answered a couple of questions talking about Non-Newtonian fluids before and you can find them under the category 'Solids Liquids and Gases: Liquids.' There is also a very interesting article that I found called, that talks a lot about what makes something a solid or a liquid or perhaps something in between. Check it out!

-Tamara

(published on 10/22/2007)

Follow-up on this answer.