A humbling inquiry experience…
How do boats float, exactly?
Buoyancy is a concept that has been wrinkling my brain for about the past month, from about a week before I started teaching it, to um, the day before the unit test. I did read the text, AND Paul Hewitt’s excellent “Conceptual Physics”. My dad who knows everything (well, at least about this, considering he’s been a physicist since just after Newton died) wrote me a two page, single spaced essay to help. And I do know the theory, displacement of water and all.
But how does the buoyant force actually work to float boats? I’m thinking of water humping up as an object is put in, and then flattening because of gravity, the flattening or ‘seeking it’s own level’ is conveyed in all directions in a fluid as pressure, including upward on the object. I think that’s the ‘buoyant force’….
And right here, I’m getting that sketchy feeling, of not having the depth of knowledge it takes to run inquiry labs well and deal with student questions in a way that clarifies rather than confuses.
Had a student say “Why don’t you teach us instead of just making us do experiments and read and watch videos?” After getting over the horrible irritation, I calmed down and suggested that he did actually read the short chapter to see if it came together, then went back over and helped him make sense of it. I guess he figured out that I was at the limit of what I could explain and was looking for a way to catch me out. Ouch. 8th grade – tough crowd!
(Add to this that Bill Nye’s Buoyancy is OMG, wrong about their explanation of displacement – sudden change of plan between 1st and 2nd period. Used “Eureka” Buoyancy instead.)
Today gave me huge insight into why many teachers will NOT try inquiry. And maybe a nudge to curriculum directors and principals to get SUBJECT/conceptual professional development as a pre-requisite to pushing inquiry teaching methods.
The Exploratorium, a premier promoter of inquiry-based learning, do not recommend it until beginning teachers get class management and the basic curriculum under their belts. The trick is then to get people to transition from what’s easier and more comfortable, towards a more student-centered and open-ended approach that is central to science.
It’s more fun with a team-mate, where you can both laugh about it, look it up and try again. And most days it’s fine, having generally a blast with the kids, much better than earlier. Have to allow myself to f-up and learn from it. Really, really want to find a good physics educator to help me. Hmm, Exploratorium staff, now there’s an idea…
Entry filed under: Class Management, Education Psychology, Inquiry and critical thinking, Physics Topics. Tags: buoyancy, density, Exploratorium, inquiry, instructional methods, labs, middle school physics, middle school science.