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Re: [Phys-L] The Make-Believe World of Real-World Physics



-----Original Message-----
From: Phys-l [mailto:phys-l-bounces@phys-l.org] On Behalf Of Anthony
Lapinski
Sent: Friday, July 12, 2013 10:19 AM
To: Phys-L@Phys-L.org
Subject: Re: [Phys-L] The Make-Believe World of Real-World Physics

Compared to most other subjects they take in high school. This is because
many physics concepts are counterintuitive. And then there's the math
element, reading/interpreting word problems, graphing, etc. Physics IS
difficult. I'm not comparing physics to "living in the real world" -- that's apples
and oranges. I'm talking about physics as a part or their academics. Toughest
(intro) subject they will take. This has been my experience.

You say many physics concepts are counterintuitive. As I get older and teach more, I am doubting that more and more. I believe that what seems to students to be "counterintuitive" is probably just a failure to actually think about what is happening. Part of improving our teaching is related to pointing the students to actually think about a situation rather than merely reacting.

One of those counterintuitive concepts may be "falling objects near the surface of the Earth accelerate at the same rate, ignoring air resistance." (Don't pounce on my wording.) What we have to do is guide the students to not think of acceleration as a "fundamental" property, but to get them to examine the force. More massive objects DO have more force on them , mg, where g is NOT the acceleration "of gravity" but the strength of Earth's gravitational field. Another concept is that the strength of the field doesn't depend on the falling object, but on Earth's mass and distance, etc. Then get them to think what the associated acceleration should be (a = F/m = mg/m = g (for a numerical answer, NOT a concept)).

As physicists teaching physics, we need to rid ourselves of the idea that physics concepts are counterintuitive and begin to develop better explanations that emphasize the intuitive basis of physics. And that's why we should oppose biologists and mathematicians who took one introductory physics course or passed some education multiple choice test from EVER teaching high school physics. I'd rather receive a student who never had physics in high school vs. one who had a poor teacher.