JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    <div class="oggetto" style="left:0px;">&nbsp;</div>
    <div class="oggetto" style="left:50px;">&nbsp;</div>
</div>

CSS

#container
{
    position:relative;
    width:100%;
    height:300px;
    overflow:hidden;
}

.oggetto
{
    position:absolute;
    top:0;
    width:10px;
    height:10px;
    background-color:blue;
    z:index:40;
}

JavaScript

var newElement=$('.oggetto').eq(0).clone();
$("#container").append(newElement); //add the element 

//Now animate
newElement.animate({ 'top': '2000px'}, 5000);