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Establish Good support system. ...Wisdom

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 Author Topic: charged particles and non uniform magnetic field/board:26-1-  (Read 34655 times) 0 Members and 1 Guest are viewing this topic. Click to toggle author information(expand message area).
danielemateriale
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 « Embed this message Reply #30 on: June 29, 2013, 10:16:54 pm » posted from:MILANO,LOMBARDIA,ITALY

sorry professor I found a possible error in the program.

if I set B = 0 to verify that the speed is correct I find that

scale of wall 600

if I put 1 (arbitrary units) = 100um i have that 10 km / s are 1 km / s
if I put instead 1 (arbitrary units) = 1000um I find that 10Km / s are 10Km / s

but if I calculate the radius of curvature with any value of sigma B and I find that 1 (arbitrary units) = 100um

where is the error, maybe in the time?

i'm sure (maybe!!! ) that the time si ten times more big of normal

1 arbitrary unit =100um yet if you put time divided by (time/10)

e.g.
default values but B=0
traiectory linear deltax=1.01 arbitrary units, time=5.05us

1 arbitray units =100um

if you choose time 5us you get 20m/s, not 0,2Km/s
if you choose time 5us/10 get 200m/s, real 0.2Km/s

default values B=1T
if you calculate the diametrer of traiectory you find
1=100um

as we told in the past

addition to the time that must be divided by 10 should improve two parameters.

1. at any scale,  the cursor speed should not exceed 100Km/s are not relistic higher speed.
2. the  time step, at any scale, must not exceed 2us at higher values ​​the simulation is very bad

thanks

 « Last Edit: June 30, 2013, 12:05:20 am by danielemateriale » Logged
danielemateriale
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 « Embed this message Reply #31 on: June 30, 2013, 03:02:56 am » posted from:MILANO,LOMBARDIA,ITALY

please also you could put a space where you can numerically enter the angle of the velocity vector (in short, choose the direction) using a numerical value

please put in the video of the programm the (down and right) the written 1=100um is much important for the user and  show with a figure the direction of B.

thanks
 « Last Edit: June 30, 2013, 03:10:20 am by danielemateriale » Logged
Fu-Kwun Hwang
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 « Embed this message Reply #32 on: June 30, 2013, 08:12:05 am » posted from:,,Satellite Provider

The time step and frame rate was not set correctly. It is done.
It will be better if you can provide a jpg/gif file which show direction for B,x,y (lower left corner)
Then, I will replace it.

Click the eye (image) to display the simulation

Embed a running copy of this simulation

Embed a running copy link(show simulation in a popuped window)
Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!
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danielemateriale
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 « Embed this message Reply #33 on: June 30, 2013, 02:49:49 pm » posted from:MILANO,LOMBARDIA,ITALY

thanks so much for the improve the simulation. i have attach a gif file for the axis.
 Assi-cartesiani modificata.gif (14.83 KB, 608x441 - viewed 343 times.) Logged
Fu-Kwun Hwang
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 « Embed this message Reply #34 on: June 30, 2013, 03:08:39 pm » posted from:,,Satellite Provider

It is updated again (in the previous message). Your image file is a large one so it is reduced in the simulation.
The X,Y,B might not be so clear.Is the size OK?
It will be better if the original image file is a small size. Or give me a image with the exact size to fit the simulation will be perfect.
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danielemateriale
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 « Embed this message Reply #35 on: June 30, 2013, 03:08:59 pm » posted from:MILANO,LOMBARDIA,ITALY

excuse professor but the problem of time persists

eg

default values ​​but B = 0

deltax = 1.35 units, deltatime = 6.784us

if we have 1 = 100um

we have 135um and divided by deltatime you get 20m / s

instead the speed that is correct, and set to 200m / s

so the time must be divided by 10 to a correct result
thanks
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danielemateriale
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 « Embed this message Reply #36 on: June 30, 2013, 03:19:11 pm » posted from:MILANO,LOMBARDIA,ITALY

this is a another gif. if you don't like tell me what you need
 Senza titolo-1.gif (10.13 KB, 451x350 - viewed 342 times.) Logged
danielemateriale
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 « Embed this message Reply #37 on: June 30, 2013, 03:26:17 pm » posted from:MILANO,LOMBARDIA,ITALY

there are other attachs
 Senza titolo-2.gif (1.95 KB, 119x93 - viewed 303 times.)  Senza titolo-3.gif (2.76 KB, 166x129 - viewed 342 times.) Logged
Fu-Kwun Hwang
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 « Embed this message Reply #38 on: June 30, 2013, 03:46:10 pm » posted from:,,Satellite Provider

The simulation has been updated with latest image file.

The mistake was from the mis-interpretation. It is correct now. (The unit for time is not us but 0.1 us, the display has been changed).

Actually, the unit used in the simulation is v(m/s), m(kg), r(m), B(T), q (1.6 C)

The default for the simulation is m=1kg, v=0.2m/s, B=1 T, q=1.6C
From $r=\frac{mv}{qB}={1*0.2}{1.6*1}=\frac{1}{8}=0.125$

However, you would like to change the interpretation.
m=1*10^{-26}kg, v=0.2 km/s, B=1T, 1=1.6*10^{-19}C
So $r=\frac{1*10^{-26}*0.2*10^{3}}{1.6*10^{-19}*1}=0.125*10^{-4}$m
That is why we call the 1 unit =100 um.

Because the unit for space become 100um, the unit for speed become km/s
So the time step is $10^{-4}/10^3= 10^{-7}$s =0.1us

It should work fine now.

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danielemateriale
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 « Embed this message Reply #39 on: June 30, 2013, 04:07:51 pm » posted from:MILANO,LOMBARDIA,ITALY

ok you are right.
 « Last Edit: June 30, 2013, 04:36:15 pm by danielemateriale » Logged
danielemateriale
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 « Embed this message Reply #40 on: June 30, 2013, 04:37:04 pm » posted from:MILANO,LOMBARDIA,ITALY

thanks now the programma work very well.
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danielemateriale
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 « Embed this message Reply #41 on: June 30, 2013, 05:00:50 pm » posted from:MILANO,LOMBARDIA,ITALY

professor thanks for your help. the program is finished.

I thank you now for I can not do nothing but offer her my services

as I said before I am able to:

- Use photoshop cs3
- Use autodesk inventor professional
. designs for mechanics
. jewelry
. laser cutting
. etc ...
- Use programs for the calculation of structural mecchanic parts
. beams
. bolts
. toothed wheels
. etc ...
- Use program for simulation of magnetic fields in 2d PERMAG
- Use simple programs for the simulation of thermal exchange in 2d now and in the future in 3d

send me a mail (ony for professor FU-Kwung Hwang) whit your request and if i can i'll do it for free.

We can became friend on facebook i have send you a request as Anto***** Daniele
 « Last Edit: June 30, 2013, 05:08:32 pm by danielemateriale » Logged
Fu-Kwun Hwang
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 « Embed this message Reply #42 on: June 30, 2013, 05:57:39 pm » posted from:,,Satellite Provider

The final version is uploaded again for easy access.

Click the eye (image) to display the simulation

Embed a running copy of this simulation

Embed a running copy link(show simulation in a popuped window)
Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

You are welcomed. I only hope the final simulation is what you really need.
Are you going to use the simulation for teaching?

It take time to fully understand what you really want. And I also learn something during the process.

Regards!

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danielemateriale
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 « Embed this message Reply #43 on: June 30, 2013, 06:23:30 pm » posted from:MILANO,LOMBARDIA,ITALY

not for teaching, other reason.

thanks for have accept my request on facebook

Do you like inventions? i like very much, from when i was a child, and I delight to do inventions in  mechanical.

I needed this simulation to see if my idea was valid or not.

it's valid!!!

thanks so much professor and if you need something in the previuos my post, as said my god, you only have to ask and you will be given
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Fu-Kwun Hwang
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 « Embed this message Reply #44 on: June 30, 2013, 07:09:59 pm » posted from:,,Satellite Provider

I hope your ideas can be realized soon!
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danielemateriale
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 « Embed this message Reply #45 on: June 30, 2013, 10:26:12 pm » posted from:MILANO,LOMBARDIA,ITALY

thanks
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Establish Good support system. ...Wisdom