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One task with 3 bobs - Forces searching

ValeryOchkov
24-Ruby IV

One task with 3 bobs - Forces searching

I try to find forces in this task. The Mathcad 15 sheet is in attach. Are equations in the Given-Find block right?

What is the 8-th equation?

3-bobs.jpg

103 REPLIES 103

Valery I'm sorry, I do not know the language. Furthermore "google translator" is not at all satisfactory.

This reference is for me.

I use PTC community as a cloud disk for my works too!

What is break - the string (the force was so big) or the function Find?

Can you plot traces points 2 and 3? Слабо?

Video Link : 7739

The last frame

3-bobs-x4.png

With 2 traces. But better not use spline - to create functions y(x):=Minimize() and y(x):=Find(). Try please!

Video Link : 7740

This movie can we see if one string is break:

Video Link : 7741

PS we have not strings but hard links!

Can you solve this task with strings not hard links? With air resistance etc? Слабо?

vlehner
14-Alexandrite
(To:ValeryOchkov)

Chaos-Pendulum.

wouldn't it be easier to create the DGL-EQN with Lagrangesche's Formalism?

Volker

Volker Lehner написал(а):

Chaos-Pendulum.

wouldn't it be easier to create the DGL-EQN with Lagrangesche's Formalism?

No problem! Create it please!

vlehner
14-Alexandrite
(To:ValeryOchkov)

...and i thought you made it allways...-meh!

Next task: Do it with the good old Abacus.

Volker

Volker Lehner написал(а):

...and i thought you made it allways...-meh!

Next task: Do it with the good old Abacus.

My late mother was able on this device (Russian Abacus) to extract the square root. Weak!

I was able to solve differential equations on such device (Robotron?) in my student years. If you divide by zero, the carriage of this device goest right to the stop and there chirped until it laboratory assistant stopped.

Robotron.jpg

With air resistance

Video Link : 7743

With air resistance end an elastic string

Video Link : 1357

vlehner
14-Alexandrite
(To:ValeryOchkov)

what a shame that there in Prime no animations are possible.

Volker

With... water resistance:

Video Link : 7748

With 3 traces

Video Link : 7742

The last frame

3-mass-trace-23.png

The correct method of traces create and plot

Fig-11-function.png

Is this model true? Can we use the minimize function here?

2-mass-1-boll.jpg

vlehner
14-Alexandrite
(To:ValeryOchkov)

Valery,

...to be serious

you changed the Geometry: Value x4 from 280mm to 340mm. Why? (better to compare with 280mm to the former problems/situations)

Setting up the 2.nd mass from 2gm to -10gm (now it it a Force upwards) doesn't (may not) corupt the Energy-Laws, so the use of the minimize-Method is in my opinion ok.

The minimal Princip of the potential energys is given by m1, m3.

Volker

The first version of the article in attach.

I have solved ODEs

see Hello, World! See my 1-st Prime Animation!

than I have deleted derivatives and got solution of same static task about 3 mass on the string

Thanks to all!

Fig-27-3-mass-4-forse.png

But no solution in Mathcad 15 - different units in vectors! Do you know solutions?

vlehner
14-Alexandrite
(To:ValeryOchkov)

When i change the guess-values, the results change or an error occurs.

The Method with minimize function is stabil at all.

Volker

Volker Lehner написал(а):

When i change the guess-values, the results change or an error occurs.

The Method with minimize function is stabil at all.

Volker! Guten Morgen!

Sorry - I have do it and get stabile results.  In Prime. Show please the picture or pdf!

vlehner
14-Alexandrite
(To:ValeryOchkov)

Guten Morgen Valery!

Please look here:

And an example for other results:

I know that the guess values are not realistic- Maybe this could be a reason for that.

Your Calculation is completely right and i can comprehend it (Thank god that the positive and negative signs in russia are the same as in germany )

Have a nice day!

Volker

It is non linear system and it can have not one solution.

Check please

3-mass-4-forse-rnd.png

Needed solution

One more solution

vlehner
14-Alexandrite
(To:ValeryOchkov)

Thank you!

Good idea with the random-function.

Volker

Last (3/05/2017) version of the article in attach!

The name

Physics vs computer science: a funicular polygon in statics, kinematics and dynamics
or
Newton vs Lagrange

I have sent it to Journal of Applied Mathematics and Mechanics - Description

Let wait for the answer!

Second variant Том 3 Номер 4 | cloudofscience.ru

vlehner
14-Alexandrite
(To:ValeryOchkov)

Great articel!

Volker

Volker Lehner написал(а):

Great articel!

Thanks!

It will be a chapter for one new book with description of main tools of Mathcad.

Toby!

The more useful for PTC title of the article is

Physics and Mathcad: a funicular polygon in statics, kinematics and dynamics
or
Newton vs Lagrange

OK?

How is the process of translation?

ValeryOchkov написал(а):

Volker Lehner написал(а):

Great articel!

Thanks!

It will be a chapter for one new book with description of main tools of Mathcad.

Toby!

The more useful for PTC title of the article is

Physics and Mathcad: a funicular polygon in statics, kinematics and dynamics
or
Newton vs Lagrange

OK?

How is the process of translation?

Or  more interesting

Physics and Mathcad in statics, kinematics and dynamic
or
Mathcad vs MMM (Maple, Matlab, Mathematica)

Volker Lehner написал(а):

Great articel!

I think you use the google translator.

Send please this parts of translations to Toby for editing.

Version from 4/5/2015 in attach

vlehner
14-Alexandrite
(To:ValeryOchkov)

Hi Valery,

Translation in German is in Progress.

Will sent it to Toby if completely finished.

Gruß, Volker

Volker
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