Damn you mathematicians

Borodog · #1 03-01-2007, 12:09 AM

Started rotational kinematics in class today. Was again reminded of this bollocks:

s = r*theta

This, and all that follows from it, drives me [CENSORED] NUTS. Do you see why?

[img]/images/graemlins/mad.gif[/img]

flipdeadshot22 · #2 03-01-2007, 12:15 AM

So you're more of a linear motion type guy I take it? What course/level is this btw?

Duke · #3 03-01-2007, 12:26 AM

First instinct: you hate radians.

Second thought: Typically this is where students start getting greek letters shoved up their asses, and you don't like phi, so you use theta instead.

Third: Kids are used to degrees, and will start screwing everything up because they aren't yet comfortable with radians.

Siegmund · #4 03-01-2007, 01:00 AM

It could be worse. Borodog could have been one of those crazy chemistry teachers who think there is some merit in using the base-10 logarithm.

Duke · #5 03-01-2007, 01:08 AM

[ QUOTE ]
It could be worse. Borodog could have been one of those crazy chemistry teachers who think there is some merit in using the base-10 logarithm.

[/ QUOTE ]

I'm still not convinced that any of my possible explanations are correct, though I'm pretty sure that it involves the teaching aspect and not just the material itself.

holmansf · #6 03-01-2007, 01:47 AM

'cause s doesn't have units length*angle. Or at least that's my guess.

thylacine · #7 03-01-2007, 01:51 AM

[ QUOTE ]
Started rotational kinematics in class today. Was again reminded of this bollocks:

s = r*theta

This, and all that follows from it, drives me [CENSORED] NUTS. Do you see why?

[img]/images/graemlins/mad.gif[/img]

[/ QUOTE ]

No.

BTW what are s, r, \theta here?

Borodog · #8 03-01-2007, 01:52 AM

[ QUOTE ]
'cause s doesn't have units length*angle. Or at least that's my guess.

[/ QUOTE ]

Bingo. The expression is dimensionally incorrect. I [censored] HATE THAT [censored].

Me for 1/2 the semester: UNITS UNITS UNITS UNITS!

Me 1/2 way through the semester: Uh, except . . .

Borodog · #9 03-01-2007, 01:53 AM

[ QUOTE ]
[ QUOTE ]
Started rotational kinematics in class today. Was again reminded of this bollocks:

s = r*theta

This, and all that follows from it, drives me [CENSORED] NUTS. Do you see why?

[img]/images/graemlins/mad.gif[/img]

[/ QUOTE ]

No.

BTW what are s, r, \theta here?

[/ QUOTE ]

Arc length, radius, and angle in radians.

thylacine · #10 03-01-2007, 02:01 AM

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
Started rotational kinematics in class today. Was again reminded of this bollocks:

s = r*theta

This, and all that follows from it, drives me [CENSORED] NUTS. Do you see why?

[img]/images/graemlins/mad.gif[/img]

[/ QUOTE ]

No.

BTW what are s, r, \theta here?

[/ QUOTE ]

Arc length, radius, and angle in radians.

[/ QUOTE ]

Of course my first guess would be that you are worried about units, but that couldn't be it because angles are obviously dimensionless. In fact this equation makes this clear. So I really can't guess what the problem could be. Please enlighten me.