連結ばね
連結ばねのシミュレート
左側の赤い正方形をドラッグして離すと、２つの箱が３つのばねによる運動を始めます。
ばね定数等の各変数はテキストフィールドにて変更できます。
/**
* Copyright Nicolas ( http://wonderfl.net/user/Nicolas )
* MIT License ( http://www.opensource.org/licenses/mit-license.php )
* Downloaded from: http://wonderfl.net/c/DWTE
*/
//連結ばねのシミュレート
//左側の赤い正方形をドラッグして離すと、２つの箱が３つのばねによる運動を始めます。
//ばね定数等の各変数はテキストフィールドにて変更できます。
package {
import flash.display.Sprite;
import flash.events.*;
import flash.text.*;
[SWF(frameRate="60")]
public class SpringTest extends Sprite {
public function SpringTest() {
//ばね
var spring1:Spring = new Spring(50, 100);
addChild(spring1);
var spring2:Spring = new Spring(200, 100);
addChild(spring2);
var spring3:Spring = new Spring(350, 100);
addChild(spring3);
//箱（おもり）
var box1:Box = new Box(150, 75);
box1.buttonMode = true;
addChild(box1);
var box2:Box = new Box(300, 75);
addChild(box2);
//ばね定数入力
var k1Text:TextField = new TextField();
k1Text.x = 80;
k1Text.y = 40;
k1Text.height = 20;
k1Text.width = 50;
k1Text.border = true;
k1Text.type = TextFieldType.INPUT;
k1Text.restrict = "0-9 .";
k1Text.text = "1";
addChild(k1Text);
var k2Text:TextField = new TextField();
k2Text.x = 230;
k2Text.y = 40;
k2Text.height = 20;
k2Text.width = 50;
k2Text.border = true;
k2Text.type = TextFieldType.INPUT;
k2Text.restrict = "0-9 .";
k2Text.text = "1";
addChild(k2Text);
var k3Text:TextField = new TextField();
k3Text.x = 380;
k3Text.y = 40;
k3Text.height = 20;
k3Text.width = 50;
k3Text.border = true;
k3Text.type = TextFieldType.INPUT;
k3Text.restrict = "0-9 .";
k3Text.text = "1";
addChild(k3Text);
//おもりの質量入力
var m1Text:TextField = new TextField();
m1Text.x = 150;
m1Text.y = 150;
m1Text.height = 20;
m1Text.width = 50;
m1Text.border = true;
m1Text.type = TextFieldType.INPUT;
m1Text.restrict = "0-9 .";
m1Text.text = "100";
addChild(m1Text);
var m2Text:TextField = new TextField();
m2Text.x = 300;
m2Text.y = 150;
m2Text.height = 20;
m2Text.width = 50;
m2Text.border = true;
m2Text.type = TextFieldType.INPUT;
m2Text.restrict = "0-9 .";
m2Text.text = "100";
addChild(m2Text);
//箱１の初速度入力
var v0Text:TextField = new TextField();
v0Text.x = 150;
v0Text.y = 200;
v0Text.height = 20;
v0Text.width = 50;
v0Text.border = true;
v0Text.type = TextFieldType.INPUT;
v0Text.restrict = "0-9, \\-.";
v0Text.text = "0";
addChild(v0Text);
//つかんで動かす
box1.addEventListener("mouseDown", drag);
function drag(e:MouseEvent):void {
//入力値を代入
spring1.k = Number(k1Text.text);
spring2.k = Number(k2Text.text);
spring3.k = Number(k3Text.text);
box1.m = Number(m1Text.text);
box2.m = Number(m2Text.text);
box1.x = 150;
box2.x = 300;
box1.v = Number(v0Text.text);
box2.v = 0;
box1.removeEventListener("enterFrame", loop2);
box1.addEventListener("enterFrame", loop1);
}
function loop1(e:Event):void {
if(mouseX>75 && mouseX<275)box1.x = mouseX-25;
//ばね描画
spring1.drawSpring(50, box1.x);
spring2.drawSpring(box1.x+50, box2.x);
stage.addEventListener("mouseUp", release);
}
function release(e:MouseEvent):void {
box1.removeEventListener("enterFrame", loop1);
box1.addEventListener("enterFrame", loop2);
}
function loop2(e:Event):void {
//ばね描画
spring1.drawSpring(50, box1.x);
spring2.drawSpring(box1.x+50, box2.x);
spring3.drawSpring(box2.x+50, 450);
//運動方程式（箱１） a = F/m
box1.a = (spring1.force - spring2.force)/box1.m;
//速度と位置を変更
box1.v += box1.a;
box1.x += box1.v;
//運動方程式（箱２） a = F/m
box2.a = (spring2.force - spring3.force)/box2.m
//速度と位置を変更
box2.v += box2.a;
box2.x += box2.v;
}
//説明用テキスト
createTextField(60, 20, "ばね1のばね定数");
createTextField(210, 20, "ばね2のばね定数");
createTextField(360, 20, "ばね3のばね定数");
createTextField(140, 130, "おもり１の質量");
createTextField(290, 130, "おもり2の質量");
createTextField(140, 180, "おもり1の初速度");
function createTextField(_x:int, _y:int, content:String):void {
var tf:TextField = new TextField();
tf.x = _x;
tf.y = _y;
tf.text = content;
tf.height = 20;
addChild(tf);
}
}
}
}
//ばね
import flash.display.*;
class Spring extends Sprite {
public var k:Number = 1;//ばね定数
public var force:Number = 0;//弾性力
public var g:Graphics = graphics;
public function Spring(_x:Number, _y:Number) {
g.lineStyle(3);
g.lineTo(100, 0);
x = _x;
y = _y;
}
public function drawSpring(startX:Number, endX:Number):void {
g.clear();
g.lineStyle(3);
g.moveTo(startX-x, 0)
g.lineTo(endX-x, 0);
//弾性力計算 F=kx
force = k*(100-(endX-startX));
}
}
//箱
class Box extends Sprite {
public var g:Graphics = graphics;
public var m:Number =100;
public var v:Number = 0;
public var a:Number = 0;
public function Box(_x:Number, _y:Number) {
g.beginFill(0xFF0000);
g.drawRect(0, 0, 50, 50);
x = _x;
y = _y;
}
}