本文實例講述了jQuery模擬物體自由落體運動的方法。分享給大家供大家參考，具體如下：
運行效果截圖如下：
點擊此處查看在線演示效果。
完整實例代碼點擊此處本站下載。
具體代碼如下：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head> <title>自由落體</title> <script src="jquery-1.7.1.min.js" type="text/javascript"></script> <script type="text/javascript" > $(document).ready(function () { }); var all_Height = 500; var a = 9.8; // 加速度 var v = 0; var prev_Time = 0; var prev_Speed = 0; var prev_Height = 0; var speed = 0; // 獲取當前的高度 var getHeight = function (obj) { return obj.offset().top; } // 獲取當前的速度 var getSpeed = function (time, a) { return time * a; } // 向下走時獲得當前物體所走的路徑 var getCurrentHeight = function (time) { return 1 / 2 * a * time * time; } // 向上走時獲得當前物體所走的路徑 var getCurrentHeight2 = function (speed, time) { return speed * time - 1 / 2 * a * time * time; } // 向下跑 function down() { prev_Time = 0; var interval = setInterval(function () { if (getHeight($(".obj")) < all_Height) { prev_Time = prev_Time + 0.1; var height = getCurrentHeight(prev_Time) + prev_Height; $(".obj").css("top", height + "px"); $(".info").append("<div>" + height + "</div>"); } else { speed = getSpeed(a, prev_Time); prev_Speed = speed; clearInterval(interval); up(); } }, 5); } // 向上跑 function up() { prev_Time = 0; prev_Speed -= 4; // 動能損耗 var interval = setInterval(function () { if (speed > 0) { speed = prev_Speed - getSpeed(a, prev_Time); prev_Time = prev_Time + 0.1; var height = all_Height - getCurrentHeight2(prev_Speed, prev_Time); $(".obj").css("top", height + "px"); } else { clearInterval(interval); prev_Height = $(".obj").offset().top; if (prev_Height < all_Height) { down(); } } }, 5); } function play() { alert('play'); down(); document.getElementById("obj").onclick = null; } </script> <style type="text/css"> body{ margin:0 0 0 0 ; background:#FFFFFF;} .title { text-align:center; color:#666666; border-bottom:2px solid gray; font-size:30px; line-height:100px; font-weight:bolder;} .obj { background-image:url('a.jpg'); width:50px; height:50px; position:absolute; top:0; left:0; } </style></head><body><div style="height:550px; border-bottom:2px solid gray;"><div class="title" >自由落體大模擬<span style="font-size:12px;">(點擊圖片讓它落下)</span></div></div><div class="obj" id="obj" onclick="play();" ></div></body></html>更多關于js運動相關內容感興趣的讀者可查看本站專題：《JavaScript運動效果與技巧匯總》
希望本文所述對大家jQuery程序設計有所幫助。
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