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Math HL IA: Designing a freight elevator

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My second portfolio is desgning a freight elevator. Does someone have the some topic as me? Any suggestions? THX :)

i have chosen the same topic for the part 2 investigation but haven started yet..wil start in few days ..from about 8th of December or something..still doing my part 1..the parabola thing..i made it too long by chance..it comes out to be around 50 pages..and m scared if it goes over the limit..btw did u start with the portfolio part 2?? plss help me if u get anything on it.. i haven yet tried it ..but i just went through it..the x-axis stimulation thing seems to be confusing..so plss do tell me if u get anything reagrding that . :D ...thnx a lot neways. :D

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I have it too, and find it almost too easy....

So just ask more specífic and i might be able to guide you into the right direction :(

But just work through the problems and you will probebly be able to solve it

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Making your own model doesn't sound too easy i think...basically i'm having problems on questions (b) and ©. I don't seem to understand what is actually happening to the elevator's velocity and acceleration during the time intervals. I don't get how there is a relationship between velocity and acceleration.

Thanks for your help.

Edited by Slayer

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Also, how do you create your own model…I’m not asking you to give me your model, but what steps do you have to go through. I was thinking first finding the ideal acceleration function, and then integrating it to get the velocity function, and integrating again, to get the displacement function. Could that possibly work? If not what method should I use ? Thanks

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Making your own model doesn't sound too easy i think...basically i'm having problems on questions (b) and ©. I don't seem to understand what is actually happening to the elevator's velocity and acceleration during the time intervals. I don't get how there is a relationship between velocity and acceleration.

Thanks for your help.

Well if you display the velocity graph on your GDC you can see that the velocity is very high at t=6, which means when the elevator comes to the surface again it has a high velocity.

As the elevator goes to a mine shaft it should probebly not go higher then the surface. And just compare the velocity and the acceleration, place them next to each other (use some better graph program if you can like advanced grapher) and you can basically tell how they relate and stuff.a

Also, how do you create your own model…I’m not asking you to give me your model, but what steps do you have to go through. I was thinking first finding the ideal acceleration function, and then integrating it to get the velocity function, and integrating again, to get the displacement function. Could that possibly work? If not what method should I use ? Thanks

What i did is to consider what kind of a model you want, there are several ways of doing. I started with the requirements that we were given. Time interval is 6, height is 80 i think according to the first model. from this you can create some points that give you a general case, now use these points to see if you can make any curve that matches this kind of motion indicated by the points.

You can use several different function (giving them a certain domain and range to work in) or use one function (for exampel a sin or cos curve)

I hoped this helps a bit, i know i am not very clear, but you should really work it out on your own, because then you get the best portfolio in the end ;)

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thewhiterider wrote (at http://www.ibscrewed.net/forum/viewtopic.php?f=2&t=15867)

Now does anyone have any answers to the questions I asked please. I don't know how to start the process of creating my own model.

after u find out the specifications and limitations of the graph given, make sure that all your limitations are removed in your new model. the given graph duzn actually represents a real life situation..so just think on what can be the changes in the graph when u consider it to be real life one. can velocity decrease so fast wherever the slope of the displacement time graph becomes too much higher

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Thanks, actually that helps a lot. I've actually found a well functioning model using a cos curve. I don't really understand what you mean by:

As the elevator goes to a mine shaft it should probebly not go higher then the surface.

You're kinda right in the end...this portfolio does seem fairly straightforward lol

Thanks for helping

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ok i need help here. how do i get the acceleration function from the position function??? also, the max of the position function is -80, not -100. wtf????

Edited by jakob//BIS

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ok i need help here. how do i get the acceleration function from the position function??? also, the max of the position function is -80, not -100. wtf????

In order to get the acceleration function, you have to take the derivative of the velocity function. And if you read the information carefully, it says "the depth of the shaft is no more than 100 metres". Using the formula y=2.5t^3-15t^2 you can find out the exact depth of the shaft, which is 80m.

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What does the last question mean..(Explain how your model may be......in other situations?)..??????????Obviously i know what it does...

But what are the other situations

Any sort of help would be appreciated

Thnk you

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Ok im doing the HL Type II Freight Elevator one

I dont understand part 1.d and part 2/3.

For 1.d., i got the usefulness but i dont see any problems?

for 2 and 3 how do i create my own function, like do i take the acceleration function first and then integrate it?

I know i should have a certain zero or concave point to show when the elevator is descending or ascending..?

Please help!!

Due in 4 days!

What does the last question mean..(Explain how your model may be......in other situations?)..??????????Obviously i know what it does...

But what are the other situations

Any sort of help would be appreciated

Thnk you

How do these models be useful in other situations??

like can you use them in hotels, but make them into a vertical line?

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Just plot the graph on some axis and you might notice that the velocity of the freight elevator is very high ones it reaches the surface again. Does that not at all seem a bit strange? Also it takes much longer time to go down then to go up?

In question two you can do several things, well first you state the conditions that need to be satisfied.

Covering that you just use a graphing programe and try to work up some function from scratch that will satisfy the model.

Most likely you will need several function i.e. your function will consist of partial functions.

One way that also works is to use a consine/sinus curve, as it is periodal. Both ways work.

I hope this helped a bit. I think there are some more posts on this problem

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Just plot the graph on some axis and you might notice that the velocity of the freight elevator is very high ones it reaches the surface again. Does that not at all seem a bit strange? Also it takes much longer time to go down then to go up?

In question two you can do several things, well first you state the conditions that need to be satisfied.

Covering that you just use a graphing programe and try to work up some function from scratch that will satisfy the model.

Most likely you will need several function i.e. your function will consist of partial functions.

One way that also works is to use a consine/sinus curve, as it is periodal. Both ways work.

I hope this helped a bit. I think there are some more posts on this problem

Hi, I'm doing this portfolio and I have done all ex. till 3. I'm stuck here, I know two points, which I need to make fit, to make cosine function to fit, but I can not find such cosine function. I thought that after finding acceleration function I will integrate it and find all others, but I can nor find accelerations. I'm stuck with making the cosine function fit my points:/ How to make a cosine function which goes exactly through some points in particular time interval ?

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Hi, I'm doing this portfolio and I have done all ex. till 3. I'm stuck here, I know two points, which I need to make fit, to make cosine function to fit, but I can not find such cosine function. I thought that after finding acceleration function I will integrate it and find all others, but I can nor find accelerations. I'm stuck with making the cosine function fit my points:/ How to make a cosine function which goes exactly through some points in particular time interval ?

Well, I used two pieces. I found that the time taken for the elevator to go down was double the time taken for it to go up, illogical much?, so i just fixed it to make the time taken to reach maximum point = time taken to reach back down to y=0

:/ don't know though....

i am kinda iffy about it

Edited by Intelligent-Bullshitter

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You guys, thanks to you I figured it out completely. Thanks!

Coolcapricon: it's asking for the original motion. Basically you graph your original expression, see why it's of no use

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