ahmedelshfie
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on: June 10, 2010, 07:52:17 pm » posted from:SAO PAULO,SAO PAULO,BRAZIL
Hi prof Hwang
I modified project
*v^2 in a physlets formula for air resistance and come to my mind idea to add slider for control in angle(theta)
So i add slider position
up name is
theta and back to equation and typing it
vx=V*Math.cos(angle/90);
vy=V*Math.sin(angle/90);
After i back again to slider theta and add the following values in image gif that I'm attach
But I'm sure have wrong because when i drag slider theta to value less 40 simulation not work
I don't know why
Could you check prof what wrong i make
Thanks
I attach also jar,,XML files of simulation
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« Last Edit: June 10, 2010, 07:54:06 pm by ahmedelshfie »
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Fu-Kwun Hwang
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Reply #1 on: June 10, 2010, 10:31:33 pm » posted from:Taipei,T\'ai-pei,Taiwan
For angle in degree from 0 to 180 is correspond cta in radian from 0 to pi.
so cta= angle*pi/180.;
where pi=3.14159 or you can define variable pi=Math.PI;// where Math.PI is a pre-defined java constant
i.e. You should use vx=V*Math.cos(angle*pi/180.);
or define a2c=pi/180.; // angle in degree to cta in radian
and use vx=V*Math.cos(angle*a2c);
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ahmedelshfie
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Reply #2 on: June 11, 2010, 12:04:16 am » posted from:SAO PAULO,SAO PAULO,BRAZIL
I do first solution that is i use variable pi=3.14159 in page basic.
And equation:
vx=V*Math.cos(angle*pi/180.);
But i notice that arrow of velocity is down by way strange down more than normally,,cant drag arrow easy for degree i want,,movement of mass slowly.
And if i use less value on slider theta simulation no work.
I don't know what wrong i do.
And i want say another point when i change value of
pi from
3.14159 to
Math.PI happend diffrent movement i can say is more good than i use pi=3.14159.
But problems about velocity arrow,,hard control in drag slider of theta and when less value on slider theta simulation no work is the same no change may is have some diffrent in movement become more fast.
I upload applet for you check prof by first value
pi=3.14159. Applet prof
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 Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a
Creative Commons Attribution 2.5 Taiwan License
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!
« Last Edit: June 11, 2010, 01:09:58 am by ahmedelshfie »
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Fu-Kwun Hwang
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Reply #3 on: June 11, 2010, 05:01:10 pm » posted from:Taipei,T\'ai-pei,Taiwan
The problem is due to code in "Fixed relation" page.
if(_isPlaying() && x>xmin+size && y _initialize(); playpause(); }
And the following code in the "initialize" page.
vx=V*Math.cos(angle/90); vy=V*Math.sin(angle/90); x=xmin+size2; y=ymin+size2; t=0.;
When you click "Play" x>xmin and y
So it execute initialize page again.
You can fix it if you modify the code in "Fixed relation" page to.
if(_isPlaying() && x>[b]xmax[/b]+size && y _initialize(); playpause(); }
and the code in initialize page to
vx=V*Math.cos(angle*Math.PI/180); vy=V*Math.sin(angle*Math.PI/180); x=xmin+size2; y=ymin+size2; t=0.;
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ahmedelshfie
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Reply #4 on: June 11, 2010, 06:17:14 pm » posted from:SAO PAULO,SAO PAULO,BRAZIL
I solve problem about control in arrow of velocity and work now very well.
But code in "Fixed relation" page.
if(_isPlaying() && x>xmin+size && y<ymin+size ){ _initialize(); playpause(); }
BY the way is the original code that i find when i begin modified simulation And code in the "initialize" page.
vx=V*Math.cos(angle*PI/180.); vy=V*Math.sin(angle*PI/180); x=xmin+size2; y=ymin+size2; t=0.;
Second code i modified but first code is original I'm no change
And i modified variable
pi=3.14159 to
PI=3.14159 When i use code you post prof ejs consul give 7 error so i back to Original code
And post for you check what wrong i made more.
About a nother problems is the same
(velocity is slowly) ,,,
when i drag slider to value less than 30 degree simulation no work .
Applet after solve problem arrow of velocity
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 Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a
Creative Commons Attribution 2.5 Taiwan License
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!
« Last Edit: June 11, 2010, 06:31:06 pm by ahmedelshfie »
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Fu-Kwun Hwang
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Reply #5 on: June 12, 2010, 10:20:09 pm » posted from:Taipei,T\'ai-pei,Taiwan
it was a bug in my original code, and it is fixed now.
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ahmedelshfie
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Reply #6 on: June 13, 2010, 12:28:57 am » posted from:Uberaba,Minas Gerais,Brazil
Yes prof
But I'm try solve problem about when i drag theta less than 30 degree
Simulation not work i don't know where is wrong
can you fix this wrong prof please
Thanks
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Fu-Kwun Hwang
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Reply #7 on: June 13, 2010, 09:08:48 am » posted from:Taipei,T\'ai-pei,Taiwan
Please upload latest ejs xml source so that I can check it out.
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ahmedelshfie
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Reply #8 on: June 13, 2010, 11:01:04 am » posted from:Uberaba,Minas Gerais,Brazil
Here is source code about last version of airdrag
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Reply #9 on: June 14, 2010, 08:58:21 pm » posted from:SAO PAULO,SAO PAULO,BRAZIL
And second applet prof is last version so i upload XML source code and have the jar file in second applet
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Fu-Kwun Hwang
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Reply #10 on: June 14, 2010, 09:28:31 pm » posted from:Taipei,T\'ai-pei,Taiwan
Initialize page:
vy=V*Math.sin(angle);
need to be modified to
vy=V*Math.sin(angle[color=red]*pi/180.[/color]);
code in "fixed relation" page
if(_isPlaying() && x>xmin+size && y<ymin+size )
need to be modified to
if(_isPlaying() && x>xm[color=red]a[/color]x+size && y<ymin+size )
Then, it should be fine (or check out attached file).
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ahmedelshfie
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Reply #11 on: June 14, 2010, 11:09:54 pm » posted from:SAO PAULO,SAO PAULO,BRAZIL
Now work very well thank you prof you the best
Last ask what is job of
K1 and
k2
« Last Edit: June 14, 2010, 11:11:47 pm by ahmedelshfie »
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Fu-Kwun Hwang
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Reply #12 on: June 14, 2010, 11:20:18 pm » posted from:Taipei,T\'ai-pei,Taiwan
The above simulation assume air drag is model with
where
is the magnitude of the velocity.
Nomally, for high speed projectile, the force is proportional to velocity square. i.e.
Howeve,for slow projectile, the force is proportional to velocity. i.e.
e.g. simulate a projectile moving under water.
User can adjust
to find a suitable model for the case s/he want to simulated and compared with the real case under studied.
And that can be one of the purpose for the above simulation. To find out a suitbale model for a real case.
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ahmedelshfie
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Reply #13 on: June 15, 2010, 12:19:15 am » posted from:SAO PAULO,SAO PAULO,BRAZIL
Very well prof thanks for information's.but i notice a thing prof in applet when
theta = 0.0 mass move to down
I mean even i don't drag slider theta and I'm just press play without drag theta simulation work but what is strange
Is mass work and fall to down
My ask how theta 0.0 and mass fall down i think mass should be move direct or not move but
Is moving down i will upload applet for you check prof
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 Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a
Creative Commons Attribution 2.5 Taiwan License
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!
« Last Edit: June 15, 2010, 01:14:33 am by ahmedelshfie »
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Fu-Kwun Hwang
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Reply #14 on: June 15, 2010, 09:39:56 am » posted from:Taipei,T\'ai-pei,Taiwan
When the initlal velocity of the projectile is in the horizontal:
Then it will move with constant speed in the horizontal direction and it will also have free fall motion in the vertical direction.
Why it should only move horizontally? or even not moving???
Let me know your argument!
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ahmedelshfie
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Reply #15 on: June 15, 2010, 05:26:08 pm » posted from:SAO PAULO,SAO PAULO,BRAZIL
I thought when i drag theta to 0.0 and initial V to 0.0
So we no have velocity or angle,so no have movement.
I mean when it should move horizontally this if we drag only initial V without drag theta,
So we will have velocity without angle in this case i think move horizontally.
However prof thanks i understand your explain now I'm just try understand every thing about simulation
« Last Edit: June 15, 2010, 06:25:33 pm by ahmedelshfie »
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Fu-Kwun Hwang
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Reply #16 on: June 16, 2010, 06:33:18 pm » posted from:Taipei,T'ai-pei,Taiwan
You did not add any action when initial velocity slider were changed.
I add _initialize() to the action. And it should work fine when you drag slider for V.
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ahmedelshfie
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Reply #17 on: June 16, 2010, 06:46:35 pm » posted from:SAO PAULO,SAO PAULO,BRAZIL
Thanks prof i fix wrong and now work very well without any wrong
Thanks
Now simulation on
Airdrag
« Last Edit: June 16, 2010, 08:27:07 pm by ahmedelshfie »
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panya.p
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Reply #18 on: January 22, 2020, 02:12:01 pm » posted from:Bangkok,Krung Thep,Thailand
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