1. Gravitational constant and Gravitational acceleration According to the law of universal gravitation, for a mass (m) on the earth,the attractive force (F) between the mass and the earth is proportional to the product of their masses (m and M), and inversely proportional to ...
The Last Waltz http://video.sina.com.cn/v/b/53026564-1043532391.html 其歌,其舞,我们是如此熟悉。 你是否知道在我们身边日日相伴的还有一只旋律最慢、舞步最大的华尔兹—— 地球自轉:多姿多采的旋舞 http://sa.ylib.com/MagCont.aspx?Unit=columnsid=1433 by 赵丰 http ...