# NTNUJAVA Virtual Physics LaboratoryEnjoy the fun of physics with simulations! Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/

## Information about this web site => Request for physics Simulations => Topic started by: juro41 on November 26, 2011, 08:46:09 pm

 Title: Torque on Pulley Due to the Tension of Two Strings/board:26-101- Post by: juro41 on November 26, 2011, 08:46:09 pm Pleas help me with this simulation. http://zamestnanci.fai.utb.cz/~schauer/contents/mechanics/rotations/ex10_4.htmlHow make this simulation. I never worked with ejs. Thanks.http://zamestnanci.fai.utb.cz/~schauer/contents/mechanics/rotations/ex10_4.html Title: Re: Torque on Pulley Due to the Tension of Two Strings/board:26-101- Post by: Fu-Kwun Hwang on November 27, 2011, 07:26:31 am How can I help? What kind of help you need? Title: Re: Torque on Pulley Due to the Tension of Two Strings/board:26-101- Post by: nobody_12 on November 27, 2011, 07:13:41 pm to sis vybral pekne tezky applet  :) Title: Re: Torque on Pulley Due to the Tension of Two Strings/board:26-101- Post by: juro41 on November 28, 2011, 10:28:06 pm Quote from: Fu-Kwun Hwang on November 27, 2011, 07:26:31 amHow can I help? What kind of help you need?Which physics formula use? And how with him manipulate objects? Title: Re: Torque on Pulley Due to the Tension of Two Strings/board:26-101- Post by: Fu-Kwun Hwang on November 28, 2011, 11:36:17 pm Do you know how to calculate the net torque $\vec{\tau}$?Then use $\vec{\tau}=I \vec{\alpha}$ to calculate the angular acceleration $\vec{\alpha}$! Title: Re: Torque on Pulley Due to the Tension of Two Strings/board:26-101- Post by: juro41 on November 29, 2011, 03:49:42 am pleas write me whole source code ... thanks Title: Re: Torque on Pulley Due to the Tension of Two Strings/board:26-101- Post by: Fu-Kwun Hwang on November 29, 2011, 07:37:42 am The simulation at http://zamestnanci.fai.utb.cz/~schauer/contents/mechanics/rotations/ex10_4.html was created with javascript calling physlet library. The source code for the physlet script is the following: Code:var timerID=0;var loaded=false;function initApplets(){ clearTimeout(timerID);        loaded=true; timerID=setTimeout("initApplet()",100);}  function initApplet(){       if(!loaded) return;       timerID=0; document.Massform.reset(); a=0; alpha=0;  document.Animator.setAutoRefresh(false);  document.Animator.setDefault();  document.Animator.setTimeDisplay(false);  document.Animator.shiftPixOrigin(130,130);  document.Animator.addObject("circle","r=20,x=0,y=0");  id1=document.Animator.addObject("circle","r=19,x=0,y=0");  document.Animator.setRGB(id1,255,0,0);  document.Animator.addLine("2*cos("+alpha+"*0.5*0)","2*sin("+alpha+"*0.5*0)","0","0");  idb=document.Animator.addObject("image","file=images/dpull.gif,x=0,y=0");  document.Animator.setTrajectory(idb,"1.5","-14");  document.Animator.addLine("0","-15-0.5*"+a+"*0","2","0");  idc=document.Animator.addObject("image","file=images/lpull.gif,x=0,y=0");  document.Animator.setTrajectory(idc,"-17","2.5");  document.Animator.addLine("-15-0.5*"+a+"*t^2","0","0","2");   document.Animator.addObject("circle","r=1,x=0,y=0"); idt=document.Animator.addObject("text","text=omega = ,calc="+alpha+"*t"); document.Animator.setDisplayOffset(idt,-130,-50); document.Animator.setAnimationSlave(id1,idt);  forcetext2=document.Animator.addObject("text","text=F"); document.Animator.setDisplayOffset(forcetext2,-20,-30); forcetext2b=document.Animator.addObject("text","text=2"); document.Animator.setDisplayOffset(forcetext2b,-13,-35); document.Animator.setAnimationSlave(idb,forcetext2); document.Animator.setAnimationSlave(idb,forcetext2b); forcetext1=document.Animator.addObject("text","text=F"); document.Animator.setDisplayOffset(forcetext1,0,-30); forcetext1b=document.Animator.addObject("text","text=1"); document.Animator.setDisplayOffset(forcetext1b,7,-35); document.Animator.setAnimationSlave(idc,forcetext1); document.Animator.setAnimationSlave(idc,forcetext1b);   document.Animator.addObject("circle","r=20,x=-18,y=-18");  id1=document.Animator.addObject("circle","r=19,x=-18,y=-18");  document.Animator.setRGB(id1,255,155,155);  document.Animator.addObject("circle","r=2,x=-18,y=-18");  document.Animator.addObject("arrow2","h=-10,v=0,x=-18,y=-16,thickness=2");  document.Animator.addObject("arrow2","h=0,v=-5,x=-16,y=-18,thickness=2");  document.Animator.addObject("arrow2","h=10,v=5,x=-18,y=-18,thickness=2");  document.Animator.setAutoRefresh(true); }function cfn11_1(){    if(!loaded) return;     f1=document.Massform.force1.value;       if( !checkRange(f1,0,10)){     alert("F1 must be between 0 N and 10 N. Your value is "+f1+" N.");     return;  }         f2=document.Massform.force2.value;       if( !checkRange(f2,0,10)){     alert("F2 must be between 0 N and 10 N. Your value is "+f2+" N.");     return;  }         mass=document.Massform.mass.value;       if( !checkRange(mass,0.1,4)){     alert("The mass of the pulley must be between 0.1 kg and 4 kg. Your value is "+rad+" kg.");     return;  }  rad=document.Massform.radius.value;       if( !checkRange(rad,0.5,4)){     alert("The radius of the pulley must be between 0.5 m and 4 m. Your value is "+rad+" m.");     return;  }  force1=eval(document.Massform.force1.value);    force2=eval(document.Massform.force2.value);    pulleymass=eval(document.Massform.mass.value);    are=eval(document.Massform.radius.value); hand1=eval(are-0.5); hand2=eval(are+0.5);    vector1=eval(are-18); vector2=eval(-18+are); arem=eval(are-0.1); radius=eval(are*10); mradius=eval(-are); radiusm=eval(are*10-1); a=eval(2*(force1-force2)/(pulleymass)); alpha=eval(a/are);  document.Animator.setAutoRefresh(false);  document.Animator.setDefault();  document.Animator.shiftPixOrigin(130,130);  document.Animator.setTimeDisplay(false);  document.Animator.addObject("text","text=Time:  ,calc=t,x=-26,y=-26"); document.Animator.addObject("circle","r="+radius+",x=0,y=0");  id1=document.Animator.addObject("circle","r="+radiusm+",x=0,y=0");  document.Animator.setRGB(id1,255,0,0);  document.Animator.addObject("circle","r=1,x=0,y=0");  document.Animator.addLine("cos("+alpha+"*0.5*t*t)*"+arem,"sin("+alpha+"*0.5*t*t)*"+arem,"0","0");  idb=document.Animator.addObject("image","file=images/dpull.gif,x=0,y=0");  document.Animator.setTrajectory(idb,hand1,"-14+0.5*"+a+"*t^2");  document.Animator.setSticky(idb,true);  document.Animator.addLine("0","-15+0.5*"+a+"*t*t",are,"0");  idc=document.Animator.addObject("image","file=images/lpull.gif,x=0,y=0");  document.Animator.setTrajectory(idc,"-17-0.5*"+a+"*t^2",hand2);  document.Animator.setSticky(idc,true);  document.Animator.addLine("-15-0.5*"+a+"*t^2","0","0",are); rid1=document.Animator.addObject("rectangle","h=20,w=20,x=-30,y=0"); rid2=document.Animator.addObject("rectangle","h=20,w=20,x=-30,y=0"); document.Animator.setForce(rid1,"0","0",-30,are,0,0);  document.Animator.setForce(rid2,"0","0",are,-30,0,0); document.Animator.setSticky(rid1,true); document.Animator.setSticky(rid2,true); document.Animator.setVisibility(rid1,false); document.Animator.setVisibility(rid2,false); document.Animator.setCollisionMessage("End of Animation"); document.Animator.setOneShot(0,5,"End of Animation"); idt=document.Animator.addObject("text","text=omega = ,calc="+alpha+"*t"); document.Animator.setDisplayOffset(idt,-130,-50); document.Animator.setAnimationSlave(id1,idt);      forcetext2=document.Animator.addObject("text","text=F"); document.Animator.setDisplayOffset(forcetext2,-20,-30); forcetext2b=document.Animator.addObject("text","text=2"); document.Animator.setDisplayOffset(forcetext2b,-13,-35); document.Animator.setAnimationSlave(idb,forcetext2); document.Animator.setAnimationSlave(idb,forcetext2b); forcetext1=document.Animator.addObject("text","text=F"); document.Animator.setDisplayOffset(forcetext1,0,-30); forcetext1b=document.Animator.addObject("text","text=1"); document.Animator.setDisplayOffset(forcetext1b,7,-35); document.Animator.setAnimationSlave(idc,forcetext1); document.Animator.setAnimationSlave(idc,forcetext1b); document.Animator.addObject("circle","r="+radius+",x=-18,y=-18");  id1=document.Animator.addObject("circle","r="+radiusm+",x=-18,y=-18");  document.Animator.setRGB(id1,255,155,155);  document.Animator.addObject("circle","r=2,x=-18,y=-18");  document.Animator.addObject("arrow2","h=-"+force1+",v=0,x=-18,y="+vector1+",thickness=2");  document.Animator.addObject("arrow2","h=0,v=-"+force2+",x="+vector2+",y=-18,thickness=2");  document.Animator.addObject("arrow2","h="+force1+",v="+force2+",x=-18,y=-18,thickness=2"); document.Animator.setAutoRefresh(true);   document.Animator.forward();}function killmenow(){ window.onerror= function() { return true;} clearTimeout(timerID); loaded=false; timerID=-1;} Title: Re: Torque on Pulley Due to the Tension of Two Strings/board:26-101- Post by: juro41 on November 30, 2011, 04:13:11 pm it is possible to convert this source code to java code? Title: Re: Torque on Pulley Due to the Tension of Two Strings/board:26-101- Post by: ahmedelshfie on November 30, 2011, 07:57:08 pm I believe you can convert any java code to java class, however you need to download program to compile i suggest DJ Java Decompiler, remember you should download java J2se sdk too.You can download DJ Java Decompiler from here http://members.fortunecity.com/neshkov/dj.html  (http://members.fortunecity.com/neshkov/dj.html) Title: Re: Torque on Pulley Due to the Tension of Two Strings/board:26-101- Post by: juro41 on December 08, 2011, 11:39:05 pm pleas if is possible send me .jar file. thanks