EarthRef.org Digital Archive (ERDA) -- DATA SHEET: Day 1: What Floats Your Boat

Description
This lesson introduces students to concepts of buoyancy, and how ships use this buoyancy to float and carry a load. They will do a hands-on exercise in buoyancy by loading and sinking small "boats" in a desktop aquaria. They will record and compare the recorded weights of both "cargo" and the amount of water needed to sink the same boat in this exercise, in order to compare densities of different substances, and to illustrate how boats can bear loads that may be larger in volume, but must be less in mass than their displacement of water.
Note that this if the first lesson in a series of five lessons with accompanying videos, collectively entitled "A Week of Science at Sea Aboard the Research Vessel Melville." The video for today is called "Life on Board a Research Vessel" and can be found in a low-resolution version on YouTube from this link http://calechoes.wordpress.com/video/. This video is most appropriate, but not required, if watched before beginning the buoyancy exercise, as it is intended to be also be an introduction to the whole five-day series. Following the video, solicit student questions, and then begin the exercise below.