Dr. Galitskiy does not understand vectors
Oct. 4th, 2004 05:21 pm"Obviously velocity of leaf will never increase to infinity. I don't believe I've ever seen this in my life. Otherwise it would be very dangerous just to go outside."
Not what you expect from your AP Physics C teacher. (By which I mean his apparent failure to understand vectors, not the quote. Of course that quote is the sort of thing you expect from Dr. Galitskiy.)
So we're doing basic mechanics, he draws a free-body diagram with a string in it, exerting a tension force T. He then writes two sets of equations - just Newton's second law, written out with all the forces involved explicitly listed - one for the block on one end of the string, one for the block on the other end of the string. Both of these, somehow, involve the term "+T". I note, you're using T to mean two different things, one to indicate the tension in one direction, one to indicate the tension in the other. Well, he says, people would get confused if I called one of them T1 and the other T2. I say, so why not just call one of them T and the other one -T? Because, he says, you can't stick a sign on a vector like that!
I, and several other people, spend quite a bit of time trying to explain to him that vectors have opposites. He doesn't seem to get the idea.
Later, he is projecting vectors along axes, and he starts writing that one thing minus another thing is this, and I say, shouldn't it be plus that? (Maybe it was the other way around.) You're forgetting about the sign of this projection. And he starts saying, no, it's the absolute value. But you didn't say it was the absolute value, you said it was the projection. And again we try to explain to him that scalars can be negative. At one point I directly said, "Scalars have sign, you know!" And he just said, no they don't.
...
Tom said the same thing happened in his class.
Dr. Galitskiy says things are "simpler" his way. They are somehow simpler when the algebra is messier, and when you constantly have to think about signs and directions of things rather than letting the algebra take care of it for you?
In other news, Day has declared one of my first two Royal Decrees to be "retarded". This does not seem a good start to my reign...
-Sniffnoy
--
"The Holocaust was an obscene period in our nation's history. I mean in
this century's history. But we all lived in this century. I didn't live
in this century."
-Dan Quayle
Not what you expect from your AP Physics C teacher. (By which I mean his apparent failure to understand vectors, not the quote. Of course that quote is the sort of thing you expect from Dr. Galitskiy.)
So we're doing basic mechanics, he draws a free-body diagram with a string in it, exerting a tension force T. He then writes two sets of equations - just Newton's second law, written out with all the forces involved explicitly listed - one for the block on one end of the string, one for the block on the other end of the string. Both of these, somehow, involve the term "+T". I note, you're using T to mean two different things, one to indicate the tension in one direction, one to indicate the tension in the other. Well, he says, people would get confused if I called one of them T1 and the other T2. I say, so why not just call one of them T and the other one -T? Because, he says, you can't stick a sign on a vector like that!
I, and several other people, spend quite a bit of time trying to explain to him that vectors have opposites. He doesn't seem to get the idea.
Later, he is projecting vectors along axes, and he starts writing that one thing minus another thing is this, and I say, shouldn't it be plus that? (Maybe it was the other way around.) You're forgetting about the sign of this projection. And he starts saying, no, it's the absolute value. But you didn't say it was the absolute value, you said it was the projection. And again we try to explain to him that scalars can be negative. At one point I directly said, "Scalars have sign, you know!" And he just said, no they don't.
...
Tom said the same thing happened in his class.
Dr. Galitskiy says things are "simpler" his way. They are somehow simpler when the algebra is messier, and when you constantly have to think about signs and directions of things rather than letting the algebra take care of it for you?
In other news, Day has declared one of my first two Royal Decrees to be "retarded". This does not seem a good start to my reign...
-Sniffnoy
--
"The Holocaust was an obscene period in our nation's history. I mean in
this century's history. But we all lived in this century. I didn't live
in this century."
-Dan Quayle
