High School Physics Lesson

On October 29 2008 11:56 Faronel wrote:
Wait, you're a high school physics teacher? WTF?

On October 30 2008 03:04 jgad wrote:
One experiment which I remember from those years involved a competition among the class. People would break into groups of two and each was given a 45° triangle bit, a big, rather floppy spring, ruler, and newton meter. The teacher had a box at the front of the class and everyone had to first analyse their spring to determine the spring constant and then to use the 45° triangle thing, along with the mass of the spring, to try to fire their spring into the box at the front of the class. It's a great experiment because it draws on gravity, springs, projectile motion - a few concepts have to work together for it to work out. Making it competitive helps to motivate the students into outdoing their peers - makes it fun.

On October 30 2008 07:58 Empyrean wrote:
Ugh.

You could've rigged up a cannon of sorts to a dropped object and demonstrated that the only acceleration in the vertical direction was 'g'. You could've shown that if you aim the cannon at the object and shoot/drop the object at the same time, you'd hit it. It's how shooters do it in competitive shooting.

We killed Gumby so many times that one day in introductory physics. Especially since my lecturer (Werner Tornow...you might hvae heard of him. Director of TUNL for a while) has a heavy German accent and started the demonstration off with "NOW HOW DO WE CALL THIS CREATURE?!?!"

XD

On October 30 2008 08:19 micronesia wrote:

Monkey Hunter problem would be too advanced 8o

On October 30 2008 09:03 Empyrean wrote:


Really? It fits right into

"5.1f The path of a projectile is the result of the simultaneous effect of the horizontal and
vertical components of its motion; these components act independently."

and it's a standard problem for introductory physics courses.

On October 30 2008 09:33 Hippopotamus wrote:
So, what happens if everyone in your class does not get a b+ or above? Do you get fired?

On October 30 2008 09:55 micronesia wrote:

It's a somewhat advanced application (relatively speaking). AP students would surely be exposed to that.


Well it's not about their grade for the year as much as their grade on the state-wide exam. But, if not enough students pass, then it definitely can cause the teacher to get fired (my five or so predecessors have been fired sequentially for that very reason)

On October 30 2008 10:09 Empyrean wrote:


What a stupid concept. If students don't perform well enough to standards, then it's pretty much their fault. You could always just curve the course. Hell, the class average on our last physics midterm was 63.5. If the school fires teachers because students aren't getting the grades they want, then the school's only hurting the students by not preparing them for college.

Seriously. There shouldn't be fixed, arbitrary numbers that are invariant and independent of the exams that determine grades. Why should the teacher make tests that always attempt to conform to the same "objective" difficulty? You shouldn't be forced to make sure that all tests basically have the same average. And distribution of scores? Another problem. I honestly can't believe that schools that that ridiculous policy that ties your hands so much.

(and as an aside, I got a 94 on that exam. -smug look- ...of course, by saying that, I just jinxed myself. I'm bound to fail the next one now )

EDIT: And your state has state-wide exams in physics? I think that's actually pretty cool. I only had state-wide math/English exams and to be honest, they were pretty stupid. I think requiring every student to have at least a basic grasp of physics is a great idea.

On October 30 2008 10:46 micronesia wrote:

If all the students were reasonably prepared for the course and motivated to pass, then that wouldn't be that big of a deal. But, when many of the students are being forced to take physics against their will, and are being told they are not allowed to drop the course even though they don't need it to meet any requirement for graduation, and they don't care if they pass or fail (in some cases) then it becomes tricky. I end up having to choose between 'drill and kill' or 'interesting and canned'

On October 30 2008 10:57 Empyrean wrote:


That's depressing...though I'm not sure I know what you by canned.

Are there accelerated courses you could be teaching?

On October 31 2008 02:16 Klockan3 wrote:
When were their base skills ever up to par?

You could think that physics is just common sense and the math is pie, but for some reason a lot of people do not really understand what they do when they learn math but instead just repeats formulas and how to apply them to the simplest of expressions and thus when they get to physics which is in general just applied math they do not get that the math they learned (And now often have forgotten) actually could be applied to a real life problem.

Like how a time derivate for position is velocity or the gradient of a potential is the force field. Most math is built on physics and therefore most physics follows the laws of math, especially calculus, but for some reason it is magic to them when you can actually apply the math to some simple physical phenomenons.

On October 31 2008 03:18 micronesia wrote:

This is a major problem with the USA's current assessment-bases system.

On October 31 2008 03:46 Klockan3 wrote:

Well, it is really hard to get an objective system which checks something as abstract as basic physical intuition. Usually people prefer an objective scale to a subjective one even if the objective scale records more or less useless knowledge.

But meh, I hardly even needed to open my physics books during high school or my first years of college so I can not really have an opinion on how to run these things. Though I really believe that others could do the same thing as long as they focused on understanding and improving their intuitions instead of just learning formulas as if they were simple glossaries made to be etched to your skull.

On October 31 2008 02:16 Klockan3 wrote:
Like how a time derivate for position is velocity or the gradient of a potential is the force field. Most math is built on physics and therefore most physics follows the laws of math, especially calculus, but for some reason it is magic to them when you can actually apply the math to some simple physical phenomenons.

On October 31 2008 11:37 micronesia wrote:

Would you be willing to clone yourself and transfer into my school? XD

Today I had a student at extra help who was having trouble with a physics problem. I asked her to read the problem step by step, and list the givens as they came up (i.e. when it says 'starting from rest' it means Vi or Vo = 0) and she got up to the statement 'accelerated at 5.0 m/s^2' and I asked her what the given was and she couldn't get it. I asked it several different ways, gave her time to think, and this was review, and she still seemed to have no idea. Nice student, but just no capability there and it drives me crazy that I'm expected to make them pass ._.

On October 31 2008 15:33 fight_or_flight wrote:
If I had to teach high school, my optimum approach would be this: There would be two ways to do well in the class. One would be primarily through homework and some tests (standard method), the other way would be primarily through tests (college method).

On October 31 2008 17:05 Klockan3 wrote:

Hmm, I guess that is what makes teachers give up trying to teach understanding and instead just gives them formulas. Did you try to explain the word "Acceleration" to her? And that m/s^2 should be read as (m/s)/s? Then you just have to take the double time integral of acceleration and you get the position/time curve, but doing the integral would probably scare her even though thats the first definition of an integral :p

Well thats one thing, I do not really understand why high school in the US have so much graded homework for the hard sciences. When I were in our high school we had several small tests and one big one for each course of math/physics but no grade based homework at all, that means that you do not need to work more than until you understand instead of forcing everyone to work until their fingers bleed.
But of course for the "lesser" students graded homework is a good idea since it forces them to study and makes it easier to pass them, but its still a dumb idea overall imo, unless it is just an optional way to pass.

On October 31 2008 21:50 micronesia wrote:
If I mentioned the word integral my boss would have a heart attack lol

When I was a student I was happy to have less hw and more heavily weighted tests... and I thought that's how it should be. What I've realized is that (at least for physics) the weaker students REQUIRE the homework in order to succeed... they will do poorly on tests if they don't have ample opportunity to try what they have learned (even though you or I would be content with a lecture and a few minutes to try it out quickly).

Regarding differentiating according to college vs grade-school style... this has been an issue I've thought about for a while. If a student is exceptional, they sometimes skip a grade. If exceptional students are allowed to bypass a year of work, why can't a student who does not skip a grade skip a smaller chunk of the workload if they can still perform on the exams? This is a no-in situation for teachers though because they can't force some kids to do more work than others (students/parents wouldn't understand and are always looking for things to complain about anyway).

On November 01 2008 00:13 Chill wrote:
My least favourite project in physics was Milikens fucking oil drop. Find the charge of an electron or something. God, you hit space bar to launch a fucking oil drop and then hope it has the right charge and use up-and-down on a program to change the plate charge until the drop stops moving. Fuck that experiment.

On October 31 2008 15:33 fight_or_flight wrote:
Grade school vs college is kind of interesting. When I was in grade school, I hated it, because my grades were based on assignments, not knowlege. I just hated spending so much time doing homework. Also, we would stay on the same topic for so long that you actually forgot the stuff from 3 weeks ago by the time you got to the test because it was so repeditive.

College was much easier for me because it was what we had to learn was strait-forward. Read the syllabus, do the listed problems, take the test.

If I had to teach high school, my optimum approach would be this: There would be two ways to do well in the class. One would be primarily through homework and some tests (standard method), the other way would be primarily through tests (college method).

If students did well on their first test, they would have the option of getting less homework graded, but having the tests more heavily weighted. If students didn't do well on the test, then they would have to do all the standard homework. Or, if they did well but didn't like heavily weighted tests, they could to homework as well.

Students who opted to do less homework would have fewer but more difficult problems.

On November 01 2008 00:30 Klockan3 wrote:

Then for what damn reason are they learning about integrals in the math courses?

Our teacher once had a test on which every question you failed you got extra homework for, thats easy to understand and none could say that its unfair.

On November 01 2008 02:02 micronesia wrote:
Just about none of my students take any calculus.

On November 01 2008 02:06 Klockan3 wrote:

Soooo, why are they then studying physics? What kind of physics class is this, for those who do not intend to study sciences at college afterwards?

On November 01 2008 02:10 micronesia wrote:

There are three main levels of physics.

Regents: mandated by the state and considered appropriate for a non-AP student (AP means advanced placement)

AP Physics B: Algebra based physics that covers slightly more topics than Regents, and goes more in-depth. Equivalent of physics course in college for non-majors and non-engineers.

AP Physics C: Calculus based physics which is approximately equivalent to the first two courses in physics for an engineer or physics major.

On November 01 2008 04:34 Klockan3 wrote:

Ah, then I see.

Checked some things, and it seems like they are just required to pick a subject. But the thing is, why pick physics? Can't you recommend them to do some other science course instead such as chemistry?

On November 01 2008 05:39 micronesia wrote:

The sequence is generally this:

9th: earth science
10th: biology*
11th: chemistry
12th physics

* sometimes biology->earth science

Students don't 'need' physics at all, but they do need at least two science (and three for the advanced diploma iirc). However, most colleges want students to do well in all of the sciences and will be less likely to accept or reward a prospective student who skipped a science. Therefore, most kids are pushed into physics even if they aren't ready for it.

On November 01 2008 09:50 Klockan3 wrote:
So in the end your job is to make stupid students look smart on paper?

On November 01 2008 10:34 Empyrean wrote:


If the students aren't ready for it, they shouldn't be pushed into doing it. The types of students who aren't ready for physics aren't the competitive ones that selective colleges really want, anyway, so there probably isn't a point in them taking any physics at all. Probably a really cynical view on the subject, but it's my opinion nonetheless.

Which is really kind of sad, since physics is such an important and interesting subject. But if students don't have any interest, I don't think the school should make them take physics. Hell, make them take an "easier" science course such as environmental studies or something. Which isn't to disparage their branch of science, but in my opinion, higher level skills such as critical thinking and application of previous knowledge just isn't used to such a magnitude as it is in a science such as physics or chemistry.

So yeah, I think making students take courses they're just not prepared for is a stupid policy on the school's part.