When teaching mechanics, we (or at least I and my teachers) stress
(endlessly) to students that the first step in analysis is to draw the
free body diagram. Yet, the buoyancy topic abandons this in favor of
using the predictive (but not casual) property of density. The switch
in analysis methods really does not help the student. Rather than
discussing 'density makes it float or sink', I get better results from
Fbuoy comes from pressure differences and can be predicted from
(rho)(g)(V) and floating and sinking, neutral results from Fb > < = W.
IMHO
Scott
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Scott Goelzer
Physics Teacher
Coe-Brown Northwood Academy
Northwood NH 03261
603-942-5531e218
sgoelzer@coebrownacademy.com
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