零桿與均佈載重

<a href="http://www.flickr.com/photos/48824177@N06/4473116270/" title="IMG_0001 by edwinfan1974, on Flickr"><img src="http://farm3.static.flickr.com/2763/4473116270_3f56ab844e.jpg" width="500" height="375" alt="IMG_0001"></a>
<a href="http://www.flickr.com/photos/48824177@N06/4473116482/" title="IMG_0002 by edwinfan1974, on Flickr"><img src="http://farm5.static.flickr.com/4015/4473116482_699ea4dd52.jpg" width="500" height="375" alt="IMG_0002"></a>
<a href="http://www.flickr.com/photos/48824177@N06/4472339983/" title="IMG_0003 by edwinfan1974, on Flickr"><img src="http://farm5.static.flickr.com/4007/4472339983_3d22658ffc.jpg" width="500" height="251" alt="IMG_0003"></a>
自修結構學發現的問題,請教各位,謝謝。
<a href="http://www.flickr.com/photos/48824177@N06/4473116482/" title="IMG_0002 by edwinfan1974, on Flickr"><img src="http://farm5.static.flickr.com/4015/4473116482_699ea4dd52.jpg" width="500" height="375" alt="IMG_0002"></a>
<a href="http://www.flickr.com/photos/48824177@N06/4472339983/" title="IMG_0003 by edwinfan1974, on Flickr"><img src="http://farm5.static.flickr.com/4007/4472339983_3d22658ffc.jpg" width="500" height="251" alt="IMG_0003"></a>
自修結構學發現的問題,請教各位,謝謝。