IA Type II -- G-Force Tolerance

[dessskris]

okay true.

mmm can +Gx and t be 0? can they be -7? can they be 8.3? can they be -20.3? can they be π? etc.

it's like stating the domains of +Gx (and +Gz) and t.

you're supposed to model a function by hand for the very first part. use your knowledge of functions (lol) to model one algebraically. start with the general formula and substitute in values of t and +Gx.

[jasmingill]

What are the tranformations that need to be done to an exponential function to get it to model the data? i have the b value as 0.944 (rounded) which i found algebraicly. how do i find a and c and d for the equation : y=ab^(x-c)+d ??

[dessskris]

actually the general formula for exponential is y=ab^x so you don't need to put c and d there

[vmfernandes13]

People were asking what the r squared value is... it's basically a significance test that shows how well your model fits the data. The numbers range from 0 to 1 and the closer to one, the better it fits the data.

I was wondering if anyone could explain how to mathematically devise a model using simultaneous equations with 5 parameters as an exponential. My equation is ab^(nx+c)+d. How do I solve that using simultaneous?!?!?! It looks scary.

Thanks for any help

[dessskris]

I was wondering if anyone could explain how to mathematically devise a model using simultaneous equations with 5 parameters as an exponential. My equation is ab^(nx+c)+d. How do I solve that using simultaneous?!?!?! It looks scary.

Thanks for any help

As I actually just said, the general formula for exponential is just y=ab^x, as simple as that. I don't know if you could model that kind of function but if you really want to, you can use substitution and elimination. It's gonna be tough, though. But I can guide you through if you are stuck

[CHARRUA]

I have some doubts about the data restrictions.

I thought that one of them should be that gforce should be positive, grater than zero. But some friends told me that they believed it should be equal or greater to zero. What do you think about it?

Secondly, time should be greater than zero, or equal/greater than zero?

Finally, what other restrictions have you found? A limted range?

Thanks 4 the help.

[TomnTom]

Hey guys,

after trying a bunch of different types of function, I finally found out that power function fit best (y=ax^b). However, now I don't know how would I reason my choice of that function in my IA. Please help !!!!

[teezkbeereh]

I realize that this function could either be a power function, an exponential function, and a log function, and I have figured out a couple of equations for the power function, but I have no idea where to continue on from there. So guidelines and help would be much appreciated!

Thanks.

Did you get the power equations by hand? If yes, how??

[dessskris]

@TomnTom google for the characteristics of power functions.

@teezkbeereh do it algebraically. start with y=ax^b and substitute in 2 sets of values of x and y. then solve them simultaneously to get a and b.

[TomnTom]

Thanks Desy !

I have one more question. I'm basically done with my paper. However, I don't get what "discuss the implications of your model in terms of G-forces acting a human being" is? Can someone please help me? Tks a lot !

[dessskris]

mmm it's like you need to generally describe your graphs in terms of G-force acting on human being.

for example:

let's say your graph looks like that, where x axis is G-force and y axis is time. I know it doesn't..but it's just an example anyway. lol

so the implication of your model is that when the force increases till let's say 1.6, the time for which human can tolerate this force will increase. when the force is 1.6, human can tolerate the force for the maximum time. when the force increases exceeding 1.6, the time for which human can tolerate this force will decrease. when the force exceeds 5, human cannot tolerate this force anymore.

as you can observe I'm actually describing the shape of the graph. but it's what they want, describing the graph in terms of G-force.

Edited May 20, 2011 by dessskris

[Noura10]

I'm doing my math IA and am using a power function as one of my models but I am wondering if power functions are on the SL 1 syllabus? I don't want to do work and then find out that I can't use the power function! What types of models did you guys use?

Thank you!

[dessskris]

I recommend the power function. it's okay if it's not in the syllabus. you are allowed to use mathematical concepts beyond the SL syllabus. maybe your teacher will even be more willing to give you high marks. maybe. good luck with it!

[TomnTom]

FINALLY DONE!

[Neko_K]

I'm doing my math IA and am using a power function as one of my models but I am wondering if power functions are on the SL 1 syllabus? I don't want to do work and then find out that I can't use the power function! What types of models did you guys use?

Thank you!

Using power functions for the first part of the task where you need to "mathematically" show how you arrived at that specific functions is a bit difficult and requires good knowledge of using curve fitting and least squares line. I suggest you just use logarithmic function for deriving the equation mathematically and then for the technology part, use your TI/Excel to get to the power function and you'll be all set. Deriving the log function is much easier, I think a sample of how to do it was shown in some of the earlier pages. Good luck

[0.o]

I don't get what parameter means!!!!

My teacher told us that therer are two types:

cotext related

mathematical: constraint which defines the model e.g. trig model: parameter is amplitude, period, and translations.

So does that mean parameter cove constrains as well?

And whats the difference between constrains and limitations?

[0.o]

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

why can't y = o

[0.o]

i am getting my 1st model function ( a power) and i chose different pairs (e.g. (35, 0.01) & (30, 4.5) then another pair (6, 10) & (15, 0.3)) to get the function and thinking of averaging it out, am i doing the right thing? i chose points so that 1 point is on the rise of the function and 1 point on the going down part of the function

Sorry if im asking so many question, but its just that its due one monday and i feel very pressured ....

THank you very much for the help!

[dessskris]

I don't get what parameter means!!!!

My teacher told us that therer are two types:

cotext related

mathematical: constraint which defines the model e.g. trig model: parameter is amplitude, period, and translations.

So does that mean parameter cove constrains as well?

And whats the difference between constrains and limitations?

if i were you i wouldn't really care about it. I'm not sure what it means either, but if you've explained the constants and coefficients in your model functions, and you've stated all the limitations you can find, you're good.

why can't y = o

well if you think that y can be 0, you don't need to believe that y can be 0.

i am getting my 1st model function ( a power) and i chose different pairs (e.g. (35, 0.01) & (30, 4.5) then another pair (6, 10) & (15, 0.3)) to get the function and thinking of averaging it out, am i doing the right thing? i chose points so that 1 point is on the rise of the function and 1 point on the going down part of the function

Sorry if im asking so many question, but its just that its due one monday and i feel very pressured ....

THank you very much for the help!

don't average them -- how could you in the first place? pick two points that you think can make a curve with a shape fitting your graph.

[0.o]

what do you menat by explain the constant and the coefficients in my model functions? Like, isn't constant & coefficientjust a number?

And the ia says "revis if necessary" what does it mean? my friends were told by their teacher that you change your model slightly to fit the data, how do you do that? like fit does not mean that my model has to go through all the data points given right? but go through nearly all and close to the ones that they don't go through

also my excel function & math SL program called two varaible statictics gives me different equations when i regressed that data table given (i triple checked to make sure everything was right) does anybody no y?

lastly as always thank u very much!