ÌâÄ¿ÄÚÈÝ
£¨15·Ö£©ÈçͼËùʾ£¬ÔÚÔÈÇ¿´Å³¡ÖÐÓÐÒ»ÇãбµÄƽÐнðÊôµ¼¹ì£¬µ¼¹ì¼ä¾àΪL£¬³¤Îª3d£¬µ¼¹ìƽÃæÓëˮƽÃæµÄ¼Ð½ÇΪ¦È£¬ÔÚµ¼¹ìµÄÖв¿Ë¢ÓÐÒ»¶Î³¤ÎªdµÄ±¡¾øԵͿ²ã¡£ÔÈÇ¿´Å³¡µÄ´Å¸ÐӦǿ¶È´óСΪB£¬·½ÏòÓëµ¼¹ìƽÃæ´¹Ö±¡£ÖÊÁ¿ÎªmµÄµ¼Ìå°ô´Óµ¼¹ìµÄ¶¥¶ËÓɾ²Ö¹ÊÍ·Å£¬ÔÚ»¬ÉÏÍ¿²ã֮ǰÒѾ×öÔÈËÙÔ˶¯£¬²¢Ò»Ö±ÔÈËÙ»¬µ½µ¼¹ìµ×¶Ë¡£µ¼Ìå°ôʼÖÕÓëµ¼¹ì´¹Ö±£¬ÇÒ½öÓëÍ¿²ã¼äÓÐĦ²Á£¬½ÓÔÚÁ½µ¼¹ì¼äµÄµç×èΪR£¬ÆäËû²¿·ÖµÄµç×è¾ù²»¼Æ£¬ÖØÁ¦¼ÓËÙ¶ÈΪg¡£Çó£º
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250049451107636.jpg)
£¨1£©µ¼Ìå°ôÓëÍ¿²ã¼äµÄ¶¯Ä¦²ÁÒòÊý¦Ì£»
£¨2£©µ¼Ìå°ôÔÈËÙÔ˶¯µÄËٶȴóСv£»
£¨3£©Õû¸öÔ˶¯¹ý³ÌÖУ¬µç×è²úÉúµÄ½¹¶úÈÈQ¡£
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250049451107636.jpg)
£¨1£©µ¼Ìå°ôÓëÍ¿²ã¼äµÄ¶¯Ä¦²ÁÒòÊý¦Ì£»
£¨2£©µ¼Ìå°ôÔÈËÙÔ˶¯µÄËٶȴóСv£»
£¨3£©Õû¸öÔ˶¯¹ý³ÌÖУ¬µç×è²úÉúµÄ½¹¶úÈÈQ¡£
£¨1£©¦Ì£½tan¦È£»£¨2£©v£½
£»£¨3£©Q£½2mgdsin¦È£![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250049451721096.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004945156893.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250049451721096.png)
ÊÔÌâ·ÖÎö£º£¨1£©µ¼Ìå°ôÔÚ¾øԵͿ²ãÉÏ»¬¶¯Ê±£¬ÊÜÖØÁ¦mg¡¢µ¼¹ìµÄÖ§³ÖÁ¦NºÍ»¬¶¯Ä¦²ÁÁ¦f×÷Ó㬸ù¾Ý¹²µãÁ¦Æ½ºâÌõ¼þÓУºmgsin¦È£½f£¬N£½mgcos¦È
¸ù¾Ý»¬¶¯Ä¦²Á¶¨ÂÉÓУºf£½¦ÌN
ÁªÁ¢ÒÔÉÏÈýʽ½âµÃ£º¦Ì£½tan¦È
£¨2£©µ¼Ìå°ôÔڹ⻬µ¼¹ìÉÏ»¬¶¯Ê±£¬ÊÜÖØÁ¦mg¡¢µ¼¹ìµÄÖ§³ÖÁ¦NºÍÑص¼¹ìÏòÉϵݲÅàÁ¦FA×÷Ó㬸ù¾Ý¹²µãÁ¦Æ½ºâÌõ¼þÓУºFA£½mgsin¦È
¸ù¾Ý°²ÅàÁ¦´óС¹«Ê½ÓУºFA£½ILB
¸ù¾Ý±ÕºÏµç·ŷķ¶¨ÂÉÓУºI£½
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004945234440.png)
¸ù¾Ý·¨ÀµÚµç´Å¸ÐÓ¦¶¨ÂÉÓУºE£½BLv
ÁªÁ¢ÒÔÉϸ÷ʽ½âµÃ£ºv£½
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004945156893.png)
£¨3£©ÓÉÌâÒâ¿ÉÖª£¬Ö»Óе¼Ìå°ôÔÚµ¼¹ì¹â»¬¶Î»¬¶¯Ê±£¬»Ø·ÖÐÓиÐÓ¦µçÁ÷²úÉú£¬Òò´Ë¶Ôµ¼Ìå°ôÔÚµÚ1¡¢3¶Îd³¤µ¼¹ìÉÏ»¬¶¯µÄ¹ý³Ì£¬¸ù¾ÝÄÜÁ¿Êغ㶨ÂÉÓУºQ£½2mgdsin¦È£
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825004945281586.png)
½âµÃ£ºQ£½2mgdsin¦È£
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250049451721096.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿