Flash / Flex / ActionScript/Animation/Acceleration

Acceleration Animation

   <source lang="java">

package {

   import flash.display.Sprite;
   import flash.events.Event;
   
   public class Main extends Sprite {
       private var _sprite:Sprite = new Sprite(  );
       private var _ax:Number = .2;
       private var _ay:Number = .1;
       private var _vx:Number = 0;
       private var _vy:Number = 0;
       
       public function Main(  ) {
           _sprite.graphics.beginFill(0x0000ff, 100);
           _sprite.graphics.drawCircle(0, 0, 25);
           _sprite.x = 5;
           _sprite.y = 10;
           addChild(_sprite);
           addEventListener(Event.ENTER_FRAME, onEnterFrame);
       }
       
       public function onEnterFrame(event:Event):void {
           _vx += _ax;
           _vy += _ay;
           _sprite.x += _vx;
           _sprite.y += _vy;
       }
   }    

}

       </source>
   
  

Start with a direction and magnitude for the acceleration force

   <source lang="java">

package {

   import flash.display.Sprite;
   import flash.events.Event;
   
   public class Main extends Sprite {
       private var _sprite:Sprite = new Sprite(  );
       private var _ax:Number = .2;
       private var _ay:Number = .1;
       private var _vx:Number = 0;
       private var _vy:Number = 0;
       var angle:Number = 45;
       var accel:Number = .5;
       public function Main(  ) {
           _sprite.graphics.beginFill(0x0000ff, 100);
           _sprite.graphics.drawCircle(0, 0, 25);
           _sprite.x = 5;
           _sprite.y = 10;
           addChild(_sprite);
           addEventListener(Event.ENTER_FRAME, onEnterFrame);
       }
       
       public function onEnterFrame(event:Event):void {
         var radians:Number = angle * Math.PI / 180;
     _ax = Math.cos(radians) * accel;
     _ay = Math.sin(radians) * accel;
           _vx += _ax;
           _vy += _ay;
           _sprite.x += _vx;
           _sprite.y += _vy;
       }
   }    

}

       </source>