ÌâÄ¿ÄÚÈÝ
ij½¨Öþ¹¤µØµÄ¹¤ÈËΪÁËÔËËÍÍßƬ,ÓÃÁ½¸ù½ØÃæΪÕý·½ÐεÄľÁÏAB?CD,Ö§ÔÚˮƽµØÃæÉÏÐγÉбÃæ,ABÓëCDƽÐÐÇÒÓëµØÃæÓÐÏàͬµÄÇã½Ç¦Á,ÈçͼËùʾ.´ÓбÃæÉ϶˽«¼¸¿éÍßƬµþ·ÅÔÚÒ»ÆðÎÞ³õËÙÊÍ·Å,ÈÃÍßƬÑØľÁÏÏ»¬µ½µØÃæ(ÍßƬ½ØÃæ¿ÉÊÓΪһ¶ÎÔ²»¡),ÏÖ·¢ÏÖÒò»¬µ½µØÃæʱËٶȹý´ó¶øÔì³ÉÍßƬÆÆÁÑ.ΪÁ˲»Ê¹ÍßƬÆÆÁÑ,ÔÚ²»¸Ä±äбÃæÇã½Ç¦ÁµÄÇ°ÌáÏÂ,¿ÉÒÔ²ÉÈ¡µÄ´ëÊ©ÊÇ( )
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241423295263791.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241423295263791.png)
A£®Êʵ±¼õÉÙÿ´ÎÔËËÍÍßƬµÄ¿éÊý |
B£®ÊÊÓ¦Ôö¼Óÿ´ÎÔËËÍÍßƬµÄ¿éÊý |
C£®°ÑÁ½¸ùľÁÏÍùÖм俿£һЩ |
D£®°ÑÁ½¸ùľÁÏÍùÁ½²à·Ö¿ªÒ»Ð© |
D
¢ÙÏÈ»³ö×°ÖõÄÕýÊÓͼ,Èçͼ¼×Ëùʾ,F1ΪƽÐÐÓÚAB?CD·½ÏòµÄ·ÖÁ¦,F2Ϊ´¹Ö±ÓÚAB?CD·½ÏòµÄ·ÖÁ¦.¢ÚÔÙ»³ö¹ýF2ÇÒ´¹Ö±ÓÚÍßÃæµÄƽÃæͼ(×¢:´ËƽÃæ²»ÊÇÊúֱƽÃæ),ÈçͼÒÒËùʾ,½«F2ÑØͼʾ·½Ïò·Ö½â,Á½·ÖÁ¦ N1= N2![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142329573666.png)
Á½Ä¾Á϶ÔÍßƬµÄ»¬¶¯Ä¦²ÁÁ¦´óСÏàµÈ,ÓÐf1=f2=
·½ÏòÏàͬ,ƽÐÐÓÚAB?CDÏòÉÏ.ÍßƬÑØBA?DC·½Ïò¼ÓËÙÏ»¬,ÓÉÅ£¶ÙµÚ¶þ¶¨ÂɵÃmgsin¦Á-f1-f2=ma,mgsin¦Á-
=ma.ÔòÏ»¬¼ÓËÙ¶Èa=gsin¦Á-![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142329729834.png)
ÈôÒª¼õСÂäµØËÙ¶È,¸ù¾ÝÌâÒâ¿É¼õСÏ»¬¼ÓËÙ¶È,ÉÏʽ±íÃ÷aÓëÖÊÁ¿ÎÞ¹Ø,¹ÊA?B´í;ÔÚ²»¸Ä±äбÃæÇã½Ç¦ÁµÄÇ°ÌáÏÂ,¿É°ÑÁ½¸ùľÁÏÍùÁ½²à·Ö¿ªÒ»Ð©,ÒÔÔö¼Ó¦È½Ç¶È,ʹa¼õС,¹ÊD¶Ô.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241423299016515.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142329573666.png)
Á½Ä¾Á϶ÔÍßƬµÄ»¬¶¯Ä¦²ÁÁ¦´óСÏàµÈ,ÓÐf1=f2=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142329682900.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142329729834.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142329729834.png)
ÈôÒª¼õСÂäµØËÙ¶È,¸ù¾ÝÌâÒâ¿É¼õСÏ»¬¼ÓËÙ¶È,ÉÏʽ±íÃ÷aÓëÖÊÁ¿ÎÞ¹Ø,¹ÊA?B´í;ÔÚ²»¸Ä±äбÃæÇã½Ç¦ÁµÄÇ°ÌáÏÂ,¿É°ÑÁ½¸ùľÁÏÍùÁ½²à·Ö¿ªÒ»Ð©,ÒÔÔö¼Ó¦È½Ç¶È,ʹa¼õС,¹ÊD¶Ô.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241423299016515.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿