Ice forming on running water

Date view Thread view Subject view Author view Attachment view

From: Christopher Reese (creese@seq.org)
Date: Tue Jan 27 2004 - 11:30:32 PST 

Message-Id: <s0164bdd.009@smtp-gw.seq.org>
Date: Tue, 27 Jan 2004 11:30:32 -0800
From: "Christopher Reese" <creese@seq.org>
Subject: Ice forming on running water

In the Hewitt video for heat, temperature and expansion he asked why ice
does not form on flowing water that is "ice cold. " Hewitt does not
know the answer in the vidoe although he does sya it can and does.

My students have asked this question in there follow-up video
questions.

I think I have an answer but want to make sure.

I think it is for 2 reasons. One, the flowing water (i.e. rapidly
moving molecules) are moving too fast for ice crystals to form. So the
water must be much colder for a significant number of molecules to form
crystals. Two, related to the first, the motion of the stream
provides addition KE that is added to the internal energy of the water,
meaning the water has to be colder.

Help.

Thanks

Christopher Reese
Science Teacher
Woodside High School
199 Churchill Ave
Woodside, CA 94062
www.seq.org/~creese
650-367-9750 x8660

Date view Thread view Subject view Author view Attachment view

This archive was generated by hypermail 2.1.3 : Mon Aug 02 2004 - 12:05:35 PDT