Re: [Phys-l] Oobleck

["John B. Laird" <laird@tycho.bgsu.edu>]

> ----- Original Message -----
> Date: Tue, 24 Feb 2009 21:28:28 -0500
> From: David Craig <craigda@lemoyne.edu>
> Subject: Re: [Phys-l] Oobleck
>
> John-
> Thanks for the concrete advice.   The club is planning on using a  
> cement mixer :-)
>
> Once mixed in the mixer, you had no trouble with the Oobleck beginning  
> to separate over that time period?

We had no trouble with the oobleck separating. That's not to say that the
mixture was perfect, which it certainly wasn't. But it seemed very
reasonable on the surface, and more importantly, the oobleck performed
just fine. I didn't observe significant changes over the time we used it.

> Do you remember what your recipe was, precisely?   (Proportions, that  
> is.)

The nominal recipe was 2 parts corn starch to 1 part water. The first year
we made oobleck we practiced ahead of time and for the actual event
measured the water fairly carefully. The second year, we added the water
directly from a hose and only estimated the ratio. We had a pretty good
idea what the consistency was supposed to be, and we were pretty
consistent from one batch to the next.

> What WAS your "suitable place to dump it"?   We've been scratching our  
> heads a bit over that....

Our suitable place was small part of a seldom used overflow parking lot
near the football stadium with a gravel/dirt surface. 

> Thanks,
> David Craig
>
>
> <http://web.lemoyne.edu/~craigda/>

John Laird