black★mage shooter » physics

Wonderland Dodger

blkmage — Fri, 19 May 2006 02:21:42 +0000

And for the second time, I’ve managed to dodge the Wonderland physics trip. Every year, the physics classes go on a trip to Wonderland to ride all of the crazy rides and calculate things like acceleration. And every year, something has saved me from going. Last year, it was the failed Streetcar Odyssey, which got cancelled last minute for our Classical Civlizations class. This year, I managed to get out of Wonderland because I’m going to Campus Challenge! Another tradition well preserved.

SIN

blkmage — Sun, 07 May 2006 02:58:36 +0000

So we wrote the Sir Issac Newton contest on the fourth of May. It wasn’t that fun and quite impossible, but I didn’t care, I’m not even going into Physics, so even if I did win, there’s no money or anything for me. But the questions were really something.

The second question had McGuinty lowering himself into a pit to save an evil reptilian kitten. Although I thought that was quite hilarious, it seems whoever wrote the question misinterpreted the Conservative release. I think that when they called McGuinty an evil reptilian kitten eater, they didn’t mean he ate evil reptilian kittens, but he was an evil reptilian who ate kittens.

Another question had Paul Martin and Stephen Harper racing bandwagons. This was probably written before January when the Liberals just fired at will at their foot, since the question had the Liberal bandwagon accelerating half as fast but having a topspeed twice that of the Conservatives.

One last question was the Olympics question, where Cindy Klassen was going to compete in levitating at Beijing. So they have the track which fits around an international sized hockey rink, which is some metres by some metres. They have Dubbya trying to stop the “international metric conspiracy” (exact words) by pushing for a slightly smaller rink that fits around an NHL sized rink which is some feet by some feet.

I wonder how many people actually found these funny.

Them Physicists

blkmage — Fri, 02 Dec 2005 21:23:15 +0000

I remember last year, Mr. Phoenix told us a story about a conversation he had with Ouzanova. They were discussing something about physics. So he wrote the equation on a chalkboard. Ouzanova then says, “That’s wrong,” and goes up to the chalkboard and adds the vector arrows above the variables. “There. Now it’s right.” The moral of the story is that physicists are a silly people, concerned with the most minute and insignificant details.

Yesterday, I had wrote a remake of a physics test. It was quite straightforward and I completed it without a struggle. Today, I get it back and find that I have quite a good mark and proceeded to find out what kind of stupid things I did to lose marks.

The first thing was when we had to find the height of the cliff in a projectile motion problem. Now, I’m sure we’re all familiar with this lovely equation:

Basically, you’re solving for the change in distance in the y direction. Since, in this particular problem, the object in question lands below where it started, the answer is going to be a negative number, even though in real life, heights of physical objects cannot be negative. So I solved for the number, got a negative result as expected, and included a note mentioning that the height of the cliff was indeed the opposite, that is, not a negative number.

And my esteemed teacher marks it wrong because it was a negative number.

Another good one is the interpretation of the acceleration-time graph. Now, when you deal with velocity, acceleration, and displacement, you deal with vectors. Vectors have both magnitude and direction, whereas scalars, like speed and distance, have only magnitude. So in interpreting the graph, there is one direction which is positive. In this case, that is north. Now, logically, when your direction is south, it is correct to say that the direction is a negative value, because you have already established that north is positive. If you so desired, you could have set south to be positive and north to be negative, but that’s up to you to decide.

So, in this lovely problem, it asks for the period of time in which acceleration is greatest. There are two sections in which the magnitudes are both 30 m/s² but the directions are different. One is heading north and the other is heading south. By the convention that has been set, the one that is heading north is accelerating at 30 m/s² [N] and the one that is heading south is accelerating at 30 m/s²[S] and therefore is accelerating (or decelerating, rather) at -30 m/s² [N]. I put my answer down that the period with the greatest acceleration is the one that is heading north.

Of course, he marks it wrong and says that there are two periods in which acceleration is greatest. And of course, when I try and argue, he says something about how those are directions and not positive or negative. Of course, that runs contrary to everything we’ve learned in physics and geometry. If you have two vectors going in opposite directions, they cannot be the same. One must be greater than the other, because their directions are opposite to each other.

So there goes three percent on my test, which is one percent on my physics mark, which is 0.17 percent on my admissions average, which I need to be as close to or over 90 as possible, and I happen to be at 89.78788897889798798 or something, so 0.17 would help very much thank you.

Damn, it’s still not June yet.