Archive for January, 2009

You Load 16 Tons, and What do You Get?

Another day older, and deeper in debt…  Or so the song goes, but is that realistic?

Man, loading 16 tons of coal in a day sounds like a lot of work… But is it as much work as it seems?

Fortunately, physics gives us a way to calculate the amount of work done.  In this case, we will assume that the only work done is to lift the coal against the force of gravity.  As the direction of motion is parallel to the direction of the force, the formula for work done is simple:

Work = Force x Distance

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Teaching Journal, Week 1

I am a TA again this semester, teaching the first semester of Physics for Biology and Pre-Medicine, which consists mostly of mechanics.  I decided to start keeping a weekly journal of the experience, how well I feel the students are learning, which things are working well, and what I need to do to improve.

Jasper over at Morning Coffee Physics apparently had the same idea that I had, and the class that he is teaching seems to be along the same lines as mine, so I will link to his posts for an interesting comparison.

Chad at Uncertain Principles is doing a similar thing for his modern physics course, so be sure to check it out for a look at what professors go through when teaching a lecture class.

Background Info:

The class is required for a variety of different majors in biology- and health/medicine-related areas, and is in many ways typical of “physics for pre-meds” classes offered at campuses all around the country.  However, the course is nominally calculus based, unlike many versions of the subject that I am familiar with.  (However, students can get by with very little knowledge of calculus, as most of it is contained in derivations, and even then, it’s mostly simple derivatives.)  Also, the professors make some effort to relate the material more directly to biological problems, even if these efforts sometimes fall flat.  I will comment on these efforts as they come up during the semester.

I teach two sections of 17 students each during a two-hour weekly lab and a one-hour weekly discussion session.  The lab topics cover the standard introductory lab topics, but with somewhat of a twist: the labs are supposed to be collaborative problem solving, rather than strictly canned labs.  This essentially boils down to the students having to decide how many data points they must take to confirm or disprove their prediction.  In addition, we’re not supposed to tell the students exactly the equations that their data are supposed to fit, although later in the last semester, I often broke down and derived the equation for them at the beginning of the lab, and explicitly told the students to check these equations.

The discussion sessions are also collaborative problem solving endeavors.  The groups are given a problem that is intended to be too involved for any of the students to solve individually.  Through collaborations, approximations, and some prodding from their TA, the students are to do their best to solve the problem.  If necessary, I will finish the session by reviewing the key topics the students were supposed to think about, and perhaps sketch a solution to the problem.  About every third week, the problem will be the first question of their quiz, which they will complete on the following day.

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New Semester’s Resolution

Did you miss the opportunity to make New Year’s resolutions?  Well, it might be a good idea to make a New Semester’s Resolution instead.  Here’s one I’m making:

The old chestnut about physics classes is that their goal is to transfer the notes from the professor’s notebook to the student’s notebooks without entering the brains of either. I think we all fall into this trap too easily – thinking that you can just get the notes down and understand it later, when it comes time to do the homework.

In some ways, the tactic of “write now, think later” is an essential survival skill, because it’s very hard to simultaneously write everything down, listen to the professor, and think critically about what it all means. In the competition between these three components, the writing is the one that usually wins out.

This strategy generally worked for me in my undergrad classes. Most of the time, I could at least write and listen, and even spend the downtime thinking about the material during class. But last semester started out differently, and I found myself blindly copying from the chalkboard a little too often. This inevitably led to late nights of using the textbook to try to decipher my notes, all while trying to solve my homework problems.

This got old, so I decided upon a new strategy, which I will embrace more fully this semester: One Class, One Question.

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Year-End Recap

This blog only came into existence in mid July of 2008, but the end of the year is a good time to take stock of what’s gone on here so far.

If you’ve been following along, or if you take a look through the archives, you’ll notice that my posting frequency fluctuates wildly.  When I set out on this venture, I had hoped my posting would be a little more regular, but the effects of grad school take their toll on how much time I can devote to the blog during certain stretches.  I am trying to fight the perfectionist tendencies that tend to slow my writing, so I may get better at churning out quick posts about things that are on my mind, but the posting frequency will certainly continue to ebb and flow a little bit.

With that said, might I recommend that, if you’ve enjoyed some of what I’ve written, following this blog via an RSS feed like Google Reader?  I know many of you already do this, but it’s a great way to keep up with sites that update irregularly without the frustration of checking sites repeatedly only to find the cupboard bare.

Below the fold are some stats about the popularity of my blog over its first few months of infancy:

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