**Date:** Tue Nov 13 13:29:50 2007

**Author:** Wallin, Stephen R

**Subject:** Re: Archimedes' Prin. and Bernoulli's Prin.

**Post:**

George,

Boy, am I behind. Anyways, here's the Arch. part. Sorry if you already had this lab.

Our approach has been to start off with a sinkable rectangular block.

Have the students estimate the volume that is going to be displaced.

From that predict the change of force due to the buoyancy upon immersion.

Actually then do it with the force sensor. (suggest objects of several Newtons)

Check that the displaced volume cause a corresponding rise in the water level upon the immersion.

Find the average density of rectangular block when doing mass / vol.

Once they have more or less verified that they can infer the displacement volume via the buoyancy, then move on to irregular object like a rock. Infer the displacement volume via the buoyancy and verify that volume caused a corresponding rise in water level.

Find the average density of irregular object knowing mass / vol.

Floating a small raft or boat with straight sides.

Putting mass into a 'boat' causes a displacement of volume corresponding to the weight of water that supports the added mass.

For entertainment float an egg on a layer between fresh and saltwater. -Stephen

stephen.wallin@coloradostate-pueblo.edu

-----Original Message-----

From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On Behalf Of George M. Caplan

Sent: Tuesday, November 13, 2007 10:57 AM

To: tap-l@lists.ncsu.edu

Subject: [tap-l] Archimedes' Prin. and Bernoulli's Prin.

We have an introductory lab on Archimedes' Prin. and Bernoulli's Prin.,

but I'd like improve it.

I'd like suggestions for good labs on these topics.