Get XML image inside Namespace

Hello, I've been trying for some days, but with no success, just get the url of the xml image below with javascript , XML this feed de noticias , to list in another area the newest posts.

<media:content url="http://blog.site.com.br/wp-content/uploads/2014/09/seo-150x150.jpg" width="150" height="150" medium="image" type="image/jpeg"/>

I was able to get the Wordpress , but the image inside a title e o link do xml is difficult, I tried in many ways and lastly I tried that way.

var media = entry['media:content'];

Code JS

dataNovo=new Date();
dataNovo.setDate(dataNovo.getDate()-10);
function loaded_feed_blog(result) {
    if (!result.error) {
        for (var i = 0; i < result.feed.entries.length; i++) {
            var entry = result.feed.entries[i];
            var dataPubli = new Date(entry.publishedDate);

            var media = entry['media:content']; //Aqui minha dificuldade            

            var div = "<div class='media'><a class='pull-left' href='" + entry.link + "' target='_blank'><img class='media-object' src='" + media + "' /></a><div class='media-body'><a href='" + entry.link + "' target='_blank' title='" + entry.title + "'><h4 class='media-heading'><span class='text'>" + truncar_texto(entry.title, 100) + "</span>";         

            if (dataPubli > dataNovo) {
            div += "<span class='label label-success'>Novo</span>";
            }
            div += "<small> - " + formatar_data(dataPubli) + "</small></h4>" + truncar_texto(entry.contentSnippet, 120) + "</a></div></div>";
            $('.changelog-container .box-content').append(div);
        }
    }
}

XML

<item>
    <title>SEBRAE e os Negócios</title>
    <link>
    http://blog.site.br/negocios-virtuais/
    </link>
    <comments>
        http://blog.site.br/negocios-virtuais/#comments
    </comments>
    <pubDate>Tue, 30 Sep 2014 18:16:07 +0000</pubDate>
    <dc:creator>
        <![CDATA[ Shopping ]]>
    </dc:creator>
    <category>
        <![CDATA[ Comércio Eletrônico ]]>
    </category>
    <category>
        <![CDATA[ Produtividade ]]>
    </category>
    <guid isPermaLink="false">http://blog.site.com.br/?p=262</guid>
    <description>
        <![CDATA[
            <p>Normalmente é assim, pelo menos na internet.....</p>
            ]]>
    </description>
    <wfw:commentRss>
        http://blog.site.br/negocios-virtuais/feed/
    </wfw:commentRss>
    <slash:comments>0</slash:comments>
    <media:content url="http://blog.site.com.br/wp-content/uploads/2014/09/seo-150x150.jpg" width="150" height="150" medium="image" type="image/jpeg"/>
</item>

EDIT:

To make namespace and chamada below:

<script src="http://www.google.com/jsapi"type="text/javascript"></script>
<script>
    function OnLoad() {
        var feed = new google.feeds.Feed("http://blog.site.com.br/feed/");
        feed.setNumEntries(5);
        feed.load(loaded_feed_blog);
    }
    google.load("feeds", "1");
    google.setOnLoadCallback(OnLoad);
</script>

HTML

<div class="row changelog-itens">
    <div class="box changelog-container alpha">
        <div class="box-header">
            <h2 class="pull-left">Direto do BLOG</h2>
            <div class="box-widget pull-right">
                <a href="http://blog.site.com.br/" target="_blank" class="btn btn-link" style="font-size: 13px; margin: 4px -10px 0 0;">Ver mais</a>
            </div>
        </div>
        <div class="box-content"></div>
    </div>
</div>

How can uso a função below, is listing right, but ver na imagem