IA Type II -- G-Force Tolerance

[HiddenDreamer]

Can someone please tell me whether time is on the x axis or y axis, because it can be argued that it can go on both axis. It would be greatly appreciated (:

I would personally say put time on the x axis and +G on the y axis.

I am working on the same task right now. I am a bit confuse with the variables, why do you chose time as the independent and +G as the dependent. thanks

Whoa I never expected such questions and I am not doing this task so I cannot comment much on it, but I hope you don't mind hearing some opinions from me.

Let me define some terms first.

Independent variable is the one which is manipulated. Meaning you can decide what their values are. The result of this manipulation leads to the measurement of the dependent variable.

Dependent variable is the one which is measured. Its values depend on the values of the independent variable.

First impression when I saw the table: time is independent and G is dependent. Why? Because most tables are organised in such a way that the first column is usually the independent variable and the second column is usually the dependent variable.

Then, the trend in the values. If you notice, the times are 0.01, 0.1, 1, 10 and also 0.03, 0.3, 3, 30 min. Don't you see the trend? But for G: 35, 28, 20, 15, 11, 9, 6, 4.5... I do not really notice any pattern in the values of G.. And if you are to choose the values of the independent variable, would you choose random numbers like 35, 28, 20, 15, 11, 9, 6, 4.5; or would you rather choose numbers in which there is a trend, like 0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30?

Last, the values of time in the first and second tables. The values are exactly the same. Thus I'd say time is the independent variable.

If you are still unsure, you may argue with me and I will try to justify my opinion

Hmm well I think that time would be dependent because in this case it seems that the test is to see how long people can last under increasing G-force. Meaning that as G-force increases people can withstand it for shorter periods of time so I see time as a responding variable meaning it would be the dependent clause. Of course this is just what I think; I am currently working on this portfolio as well...

[DaaeDore]

Hmm well I think that time would be dependent because in this case it seems that the test is to see how long people can last under increasing G-force. Meaning that as G-force increases people can withstand it for shorter periods of time so I see time as a responding variable meaning it would be the dependent clause. Of course this is just what I think; I am currently working on this portfolio as well...

I don't think it matters much which variable goes on which axis, because time and G-force are just conditions that combine to result in something else (physical state of humans). The point of the graph is not to see the amount of either variable; we just want to see their relationship with respect to each other. Usually, the amount of whatever the dependent variable is is being graphed, and in this case time would usually be the independent variable if it is causing the change in the other variable. But that's not the case in these functions, so I don't think a standard Cartesian plane is an ideal graphing medium... But we really don't have much choice. I hope this makes sense, and I hope I haven't confused you more. And I'm not a math whiz, so I'm not really sure if I'm right anyway.

[whattheheckk]

I got this portfolio 2 weeks ago, starting it today, & it's due tomorrow ...

Been reading through the posts & I guess what people are coming up with is exponential/logarithmic/power functions to represent the data

Is it okay to try to justify the use of a power function if I haven't even learned about it in class ..?

Or would it be better to simply use (what people are saying is) a less accurate model -- i.e. exponential -- since it's something I learned?

My teacher is a hardcore work-it-out-yourself kind of person, and would probably suspect plagiarism if any of us came up with an answer we never talked in class about

.. and what is regression on a GDC? How do we use it and what does it do? [concise explanations or links to websites would be helpful]

We never learned this in class either ..

All-nighters FTW

[IBstudent101]

So what are constraints for the data given? Is it the domain and range??

I have been told that the parameters would be the window and the constraints are the domain and range.

But, how would you get the window if you haven't graphed it yet?

Also, this is off topic, but does anyone know of a program where I could graph two functions BUT one of them has an equation and the other is just a set of points?

I got this portfolio 2 weeks ago, starting it today, & it's due tomorrow ...

Been reading thru the posts & I guess what people are coming up with is exponential/logarithmic/power functions to represent the data

Is it okay to try to justify the use of a power function if I haven't even learned about it in class ..?

Or would it be better to simply use (what people are saying is) a less accurate model -- i.e. exponential -- since it's something I learned?

My teacher is a hardcore work-it-out-yourself kind of person, and would probably suspect plagiarism if any of us came up with an answer we never talked in class about

.. and wth is regression on a GDC? How do we use it and what does it do? [concise explanations or links to websites would be helpful]

We never learned this in class either ..

:rip: :rip: :rip: All-nighters ftw

I am pretty sure you should ask your teacher about the whole power regression thing. Tell your teacher that you stumbled across it and if you research what it is, can you include it in the portfolio?

And do you have a TI calculator?

[whattheheckk]

I am pretty sure you should ask your teacher about the whole power regression thing. Tell your teacher that you stumbled across it and if you research what it is, can you include it in the portfolio?

And do you have a TI calculator?

Can't ask my teacher 'cause the portfolio is due tomorrow and I started it today.

& oh okay, I'll just include a footnote reference or something regarding the power function..

& yeah, I'm using a TI-84 Plus GDC. Just looked up a clip on how to use regression but its purpose is still unclear to me. Ok, so from what I gather you use regression to estimate the values of variables -- but then what? Do you just accept those values as correct? (What would you do to adjust, etc.)

PS. the lady in the clip was using a linear equation. If I want to explore an exponential function, what should I do?

Edited March 22, 2011 by Desy ♫

[IBstudent101]

Can't ask my teacher 'cause the portfolio is due tomorrow and I started it today.

& oh okay, I'll just include a footnote reference or something regarding the power function..

& yeah, I'm using a TI-84 Plus GDC. Just looked up a clip on how to use regression but its purpose is still unclear to me. Ok, so from what I gather you use regression to estimate the values of variables -- but then what? Do you just accept those values as correct? (What would you do to adjust, etc.)

PS. the lady in the clip was using a linear equation. If I want to explore an exponential function, what should I do?

Wow, this is definitely out of my expertise, but I would guess that once you input your data into your calculators and graph different regressions such as power or exponential, it just basically shows you what the graph of that data would look like put into a power equation/formula etc. I don't really know how to adjust it, actually and that will be a problem once I get to answering that part, but for example (again taking guesses here), lets say you input your data from the table and graph an exponential regression. Then you check to see how well it actually fits your data points and your y values are off by about 2, you could just go into your y1 and add a plus 2 at the end, which will move your graph vertically 2 units up.

UGHH i can't wait until this is over!!

[whattheheckk]

LOL ergggg okay thanks, that helps a little~

& me neither -- can't wait til this is over

[IBstudent101]

LOL ergggg okay thanks, that helps a little~

& me neither -- can't wait til this is over

Btw, what are constraints? domain and range??

[whattheheckk]

LOL ergggg okay thanks, that helps a little~

& me neither -- can't wait til this is over

Btw, what are constraints? domain and range??

Um, I was told that 'parameters' meant the variables+their units & the domain/range, while 'constraints' basically meant limitations -- for example, humans can only withstand up to a certain G-force, so I guess you would say that the graph doesn't extend to infinity or something.

What have you been told?

[IBstudent101]

Um, I was told that 'parameters' meant the variables+their units & the domain/range, while 'constraints' basically meant limitations -- for example, humans can only withstand up to a certain G-force, so I guess you would say that the graph doesn't extend to infinity or something.

What have you been told?

I have been told:

variables: state which is which. so time is dependent and is y and g-force is independant and is x and blah blah blah

parameter: I started writing about how time can't be negative and how g-force can't either (b/c its a POSITIVE horizontal g-force)

constraints: to write about the domain and range. like y cant be 0 and what now

[whattheheckk]

Ok I've decided to start off using a logarithmic function, but all the graphs I've seen go into the negatives on the y-axis (which I know isn't possible considering my data)..

The form I learned was y = log_bx .. am I doing this wrong?

[IBstudent101]

Ok I've decided to start off using a logarithmic function, but all the graphs I've seen go into the negatives on the y-axis (which I know isn't possible considering my data)..

The form I learned was y = log_bx .. am I doing this wrong?

as far as i know in equation form that is right. but just remember when you put it into y1 to do your graph, its logx/logb

I think I will stay away from log graphs b/c im not too sure about them..

[vlclausen]

I don't understand how the first graph looks like a log function. Everyone says it does, but how do I explain that for the people who are grading it? Cause everyone else said so?!?

[Keel]

I don't understand how the first graph looks like a log function. Everyone says it does, but how do I explain that for the people who are grading it? Cause everyone else said so?!?

In the case were you have time of tolerance on the x-axis and G-Force on the y-axis: If you draw a f(x)=ln(x) or f(x)=log₁₀(x), reflect it on the x-axis (make it f(x)=-ln(x)) and shift if up by c (f(x)=-ln(x)+c) you will get something similar. Thus the formula should be f(x)=-log_r(x)+c

In the case were you have G-Force on the x-axis and time of tolerance on the y-axis: If you draw an exponential function e.g. f(x)=2^x and reflect on the x-axis i.e. f(x)=2^(-x), you will get something similar. Thus the formula should be f(x)=r^(-x)+c.

[Swiper]

Hi,

I was wondering how you solve the system of equations for the first two data sets (35,0.01) (28,0.03)

any help would be greatly appreciated.

nvm, found out how

Edited March 19, 2011 by Swiper

[pirate]

Hi I am currently working on this portfolio and need a little help, any kind of pointers will be appreciated. Specifically i need help finding a function. i graphed the points and want to use the general equation for a power function, what do i plug in though? for a, x, or b?

BTW is the function exponential?

Actually, I personally suggest a logarithmic function.

You first need to say that you are going to model a logarithmic function. Mention the general function, y=a+b*ln(x)

Then do some calculations to find the values of a and b.

After you get the function, plot it and comment on how well it fits the data, then use a graphing software to find a power function. Briefly describe what to do in the graphing software and put a screenshot of that software showing the power equation.

However if you still want to model a power function, the general formula would be y=a^bx+c+d

Then substitute 4 sets of values of x and y (which actually are t and G respectively) and solve for a, b, c and d

Further questions are welcomed

I'm not sure what you mean by solving for a, b, c and d in the power formula. I don't know if it's just me, but how are you supposed to solve something with 4 unknown variables? i know you said before you'd substitute x and y in with the time and g-force numbers so it'd look something like 35 = a^b(0.01)+c+d right? But where are you supposed to go from there O_o It's been almost a year since i really worked with logs so i'm a bit at a loss of where to go from here to find the a,b,c and d.

---

I might not be understanding your question correctly but I suppose simultaneous method in this context should be solving equations simultaneously using elimination or substitution or matrices.

if that's true, then how are you supposed to solve a system of equations with matrices? we're just learning them now, but i'm not sure how you'd go about that

[dessskris]

@pirate sorry I'm taking too long to reply.. and sorry I'm too lazy to type the equations in BBcode that I give the reply in a picture format:

[Kristen Goodman]

I did a power regression function first and now I have no idea how to do the log function for this data with technology. Any suggestions?

[dessskris]

I did a power regression function first and now I have no idea how to do the log function for this data with technology. Any suggestions?

That's okay. Use your GDC or a graphing software to find best fit log regression.

I suggest using your GDC, especially if you have TI.

[Rock-world-IB]

Hi everyone....i have the same prompt, but i am having trouble identifying the main purpose of this Task....HELP!!!!!