用flash professional变速运动的动画

新建空FLASH把下面代码放到第一帧
平抛运动：
var speed:Number = 3;//水平初始速度
var g:Number = 9.8;//重力加速度
var interval:Number = 0.1;//时间间隔
var time:Number = 0;//开始时间
var s_x:Number = new Number();//球的横坐标
var s_y:Number = new Number();//球的纵坐标
_root.createEmptyMovieClip("ball", _root.getNextHighestDepth());
with (ball) {
_x = 0;
_y = 0;
beginFill(0xff0000, 100);
for (var i = 0; i<360; i++) {
lineTo(10*Math.sin(i/180*Math.PI), 10*Math.cos(i/180*Math.PI));
}
endFill();
}
//在舞台上画出一个球来
function s1(speed:Number, time:Number):Number {
return speed*time;
}
//水平移动s1=v*t;
function s2(a:Number, time:Number):Number {
return 1/2*a*(Math.pow(time, 2));
}
//垂直移动s2= 1/2*g*t*t;
_root.onEnterFrame = function() {
ball._x += s1(speed, time);
ball._y += s2(g, time);
time += interval;
trace(ball._x);
trace(ball._y);
};
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