I can't find the reference now, but in the 1980's, there was a study done on honors physics students -- undergraduates IIRC -- at Johns Hopkins. They were asked questions that they had the physics training to answer, but that were not problem set or exam questions. For instance: Coil a garden hose in a spiral, then force a ping pong ball out through the hose from the center to the periphery with a blast of air; how does it move once it leaves the hose: (a) continues in spiral (b) straight out - the tangent of the spiral where the hose ends (c) bending outward, away from the spiral.
Some large percentage of the students got it wrong. Explanations: (i) students limited their "physics know-how" to the textbook context, and this was something different; (ii) textbook problem sets are, over time, edited to weed out confusing problems, even if they're valid.
I've encountered something similar in teaching basic financial present value analysis to engineers - even the students who do well in the class go back to "folk" thinking when we discuss their mortgages and credit cards.
To me, it says that the cue of the classroom, or the awareness that "this is part of Physics 101" is critical to getting some people to apply a particular frame, and without that cue, they go back to "common sense". That does explain what happened (in the blog post) in the Philosophy class, and in the phone poll, but not as well what happened when the blog author tested her physics students.
From a simple F=m*a standpoint maybe, but I'm thinking that the hose would probably put a spin on the ball so it would likely curve outwards?
A ball with no spin on it would travel straight outwards because there would be no force acting on it to make it curve in any other direction.
I think a ball with spin on it would curve outwards because the ball would rotate the air around itself, which would provide the force needed to accelerate it outwards.
Some large percentage of the students got it wrong. Explanations: (i) students limited their "physics know-how" to the textbook context, and this was something different; (ii) textbook problem sets are, over time, edited to weed out confusing problems, even if they're valid.
I've encountered something similar in teaching basic financial present value analysis to engineers - even the students who do well in the class go back to "folk" thinking when we discuss their mortgages and credit cards.
To me, it says that the cue of the classroom, or the awareness that "this is part of Physics 101" is critical to getting some people to apply a particular frame, and without that cue, they go back to "common sense". That does explain what happened (in the blog post) in the Philosophy class, and in the phone poll, but not as well what happened when the blog author tested her physics students.