fwd: beat: douchey math teacher doesnt understand math (

[boost]

posted on 2+2 because I figured Id get more responses/ mspaints. Go give it a kickstart or post your mspaints here. Holla.

[gabe]

wait what

[chardrian]

Holla!! (But I don't know why)

[givememyleg]

maybe you should post the message too?

[lolzzz_321]

http://forumserver.twoplustwo.com/sh...gonew=1#UNREAD

[lolzzz_321]

Disputed problem from test below **

Ok so I have to take intermediate algebra here at culinary school. I havent taken math since junior year of highschool, about 5 years ago. I dont particularly like math, but its good to have a refresher course. Its all pretty simple stuff so far.

Anyways, the teacher is some schmuck thats not permanent staff, but instead just a temp like most of the gen ed people here. Hes constantly doing stuff on the board and messing up. Making things that should be negative positive and vice versa. He always gets a bit flustered when he is corrected and gets really defensive. This has gone on for a few weeks and Ive come to the conclusion that he is just and incompetent jerktard that cant bear to be incorrect.

So today we get a test back. A lot of the problems were on previous quizes. One of which I got wrong both times, yet both times I thought I gave a good answer. The one on the test I think was perfect. While we are going over the test Im trying to ask about this question and he gets upset and says hes not going to go over each problem right now, but after we finish going over the test as a class he will talk to us individually. This seems retarded to me because clearly lots of people had problems with this, but whatever hes the teacher not me. When he did do this problem on the board though I realized that without a doubt he is a retard and doesnt understand math and/or very very basic physics. When I got a chance to talk to him one on one he pretty much blew up, and in return I bluntly told him that he doesnt understand basic physics if he still thinks his answer is correct. He goes off and I just tell him Im leaving and Ill have a word with my dean.

**Anyways, heres the problem:
Air is blown into a balloon. The balloon is then tied so that no air can enter or leave it. If the balloon is squeezed, the air pressure inside increases. Let P be the air pressure (in pounds per square feet) inside the balloon when the baloon's volume is V in cubic inches. Sketch a graph that shows the relationship between the variables defined. Justify your graph.

I encourage bbv4lyf to mspaint answers (serious or not) and after a few are posted Ill post my two answers and then the teachers.

[Chopper]

i would tell him that if it didnt involve ounces, liters, or odds to a flush on the flop, his examples mean nothing to me.

and as far as him being a dumbass, i would challenge him to HU for $50 right now.

and, i'd prolly flunk the class.

[lolzzz_321]

[a500lbgorilla]

Pv = nRT
n and R are constant since no air enters or escapes the balloon.

The process of squeezing the balloon is reversible but not adiabadic meaning that there is some non-zero heat transfer between your hands and the balloon wall and again from the balloon wall and the air. Though this variation will be several orders of magnitude too small to consider. So T can be assumed constant.

So the equation is

Pv = c

or that P = c/v which is not a straight line but instead a big curvy C. As volume approaches zero, pressure should approach infinity and as pressure approaches zero, volume should approach infinity. None of your answers are correct.

Your first answer is an excellent approximation if you consider that the balloon can not approach either infinite or zero pressure or volume. Though, it would be better if it was not linear.

[Chopper]

yeah, upon further review (meaning more serious this time), i dont get it.

the part that confuses me is how can we blow air into the balloon in pounds per SQAURE feet and ask for volume in CUBIC feet? when operating a leaf blower the ratings are in cubic foot pounds, but when we fill our car tires, we put in psi? already a confusing premise for me.

but, i would think the answer cannot be linear. i would think it parabolic/exponential.

as for the teacher, you cant make volume or pressure reach absolute zero.

and, if the balloon is sealed, how do we change the volume by squeezing it? apply pressure unevenly and the balloon self-regulates.

the question is flawed from the start. god, i hated school. i need a beer now, thanks.

back to the lighter side...however, if said balloon didnt regulate itself, how did the clown get the fucked up bunny rabbit shape out of a hot dog shape?

THATS YOUR REAL PROBLEM, MAN!!

[lolzzz_321]

Ok this is remedial math so I'd be happy if my kids knew it was inverse in some way!

[givememyleg]

[kingnat]

I think this question is complete and utter shit...

[swiggidy]

I think this question is complete and utter shit...

agreed. To a certain extent (minimal pushing) I would think the pressure/volume would barely change, only the shape would chage. But whatever I play with electricity.

Boost, look on the bright side. They didn't ask you about circles.

[swiggidy]

This is awesome (lifted from link)

[Jibalob]

Let P be the air pressure (in pounds per square feet)

Are you living in a two-dimensional universe or is this guy just a complete retard?

Other than that and the fact that the teacher seems to think that you can create a vacuum inside a sealed and inflated balloon, and also seems to think that you can compress a sealed and inflated balloon to the point that it vanishes completely (and still somehow manages to keep a rather high internal, two dimensional air pressure) I would say he understands physics perfectly.

[a500lbgorilla]

Let P be the air pressure (in pounds per square feet)

Are you living in a two-dimensional universe or is this guy just a complete retard?

Other than that and the fact that the teacher seems to think that you can create a vacuum inside a sealed and inflated balloon, and also seems to think that you can compress a sealed and inflated balloon to the point that it vanishes completely (and still somehow manages to keep a rather high internal, two dimensional air pressure) I would say he understands physics perfectly.

What?

Firstly, pressure is a force per unit area.

Secondly, the fact that his graph actually intersects either axis demonstrates he completely lacks an understanding of physics.

Thirdly, what?

[kingnat]

Secondly, the fact that his graph actually intersects either axis demonstrates he completely lacks an understanding of physics.

So are you treating air as an ideal gas or not?...

[swiggidy]

Secondly, the fact that his graph actually intersects either axis demonstrates he completely lacks an understanding of physics.

So are you treating air as an ideal gas or not?...

it doesn't matter

[IowaSkinsFan]

Ja is right, teacher is wrong, 2nd answer Ja gave is wrong but I understand how he came to it.

[kingnat]

Secondly, the fact that his graph actually intersects either axis demonstrates he completely lacks an understanding of physics.

So are you treating air as an ideal gas or not?...

it doesn't matter

I agree that was retarded... watching football, playing cards, and typing screw me up... when I started the message I was intending to draw emphasis to the inverse relationship of the ideal gas law, rather than the linear graph... (like 500lb and others had done so above...) I was trying to suggest that the teacher expected students to use some "simpler" relationship that has a decreasing linear relationship, although I have no clue what that would be... I agree that the points on the axis are totally stupid... but it's not surprising that an equation person using a simple P = -cV equation would think it has end points on the axises. Why should math people ever consider the physical consequences of a particular formula?

I still think the question itself is awful...

[ensign_lee]

I'm pretty sure the answer is A if the answer has to be linear and not something else.

Weeeh absolute 0 volume and absolute 0 pressure!

[flomo]

this thread sucks

no titties

[Lukie]

head asplode

[IowaSkinsFan]

Yeah if the answer wasn't linear it would resemble the function f(x)=1/x which would be asymptote to the x and y axis, but that answer wouldn't make any sense, since if volume decreases pressure doesn't increase at an increasing rate.

[kelly_kabob]

As far as I recall my chemistry and based on the info...

Pressure x Volume = constant

ie. P1 x V1 = P2 x V2 = constant

If one goes up, the other goes down. Graph will resemble f(x) = 1/x.

1) Put it in Excel and make a table with PV constant and change one of the variables.
2) Make X-Y Scatter graph
3) See if your teacher was wrong

[a500lbgorilla]

Secondly, the fact that his graph actually intersects either axis demonstrates he completely lacks an understanding of physics.

So are you treating air as an ideal gas or not?...

it doesn't matter

I agree that was retarded... watching football, playing cards, and typing screw me up... when I started the message I was intending to draw emphasis to the inverse relationship of the ideal gas law, rather than the linear graph... (like 500lb and others had done so above...) I was trying to suggest that the teacher expected students to use some "simpler" relationship that has a decreasing linear relationship, although I have no clue what that would be... I agree that the points on the axis are totally stupid... but it's not surprising that an equation person using a simple P = -cV equation would think it has end points on the axises. Why should math people ever consider the physical consequences of a particular formula?

I still think the question itself is awful...

Yah, but i said he didn't understand physics, not mathematics. If he's allowing for a only linear approximation of some inverse relationship (not bound by any physical constraints), yes it will cross the axis at some point.

[boost]

yah, the question is fucked. The qusetion should have been about a cylinder with a piston being pushed down. And yah, I can see that the equation is not linear now. If you are not accounting for the balloon popping or the cylinder busting, then the graph would just look like a exponential decline (dont know if thats what its really called but w/e.) Either way the line will never intercept the axis.

Moreover and more importantly, if he insists that his graph is correct, then mine too should be correct seeing as it is more true than his. And if he didnt erroneously mark me wrong the first time, I would have answered the same (correctly if his standards were not screwy) the second time. Pretty much he is lacking any basic people skills as well as any basic math/science skills.

[IowaSkinsFan]

I'm pretty sure the relationship is best modeled linearly rather than 1/x. It's not like as we squeeze the ballon more the pressure increases at an increasing rate no? Or is this not the case?

[boost]

actually it is. Like I said the balloon is a terrible example, but think of a sealed cylinder with a piston in it. You press down on the piston and it is relatively easy to begin. Think when it gets to the point were its difficult to push, you only have to decrease the volume by a bit to increase the pressure at a greater rate. If it were linear it would be just as easy to push the piston down as it approaches the retaining wall as it was when it was fully uncompressed.

[IowaSkinsFan]

ahhh i c makes sense.