Friday, September 09, 2011

I am done with motion

If you want to call me crazy, the line forms to the rear.

But we had our first unit test today in Rio's Physics 1 course, so as of 2:50pm on Friday, September 9, we are done with motion. On Monday, we move on to Newton's laws and physics!

Kinematics can be many kinds of fun. But for my taste, it's not worth one month while the curriculum clock is ticking. It's applied math, for heaven's sake! And no, it's not the foundation upon which the entirety of introductory physics rests.

Is acceleration a difficult concept for first-year physics students to learn? Absolutely. I rank it as the most difficult concept students will confront in intro physics. So you can spend a month teaching it while mastery continues to elude many students.

But why would you?

Which part of the sky will collapse behind your students not mastering the subtle intricacies of the second derivative of the position function? None of it!

Universal mastery of acceleration is not required before you can pull out of the harbor of kinematics and set sail in the ocean of physics. So don't sacrifice one tenth of your school year chasing such mastery while engaging topics in actual physics get pushed off the table at the other end of the year.

You've got 180 days and a full palette of robust physics topics to get to. Pre-newtonian applied math does not merit an expenditure of 18 of those days. Tempus fugit! Is mastery of kinematics so important that any talk of rainbows, mirages, or the blue sky should be banished from the intro course? Or is it electricity and magnetism that should be left behind? Shall we presume that All Things Heat & Thermo are covered in chemistry, so it's OK to skip any/all such material in physics?

Something must be thrown under the bus if kinematics mastery is to be achieved. What should it be?

Whatever it is, I've got a nickel that says it's a more "legitimate" physics topic than acceleration. So my advice is to ditch the ticker-tape and (I'll say it) robust video motion analysis of projectile trajectories. That stuff might be all manner of groovy, but it's overkill in the introductory course. Few high school students need to master kinematics to secure their future career. Those who do will have more chances in college to lock such things in. In the meantime, the clock is ticking on your 180 days.

Don't keep physics waiting!

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