ÌâÄ¿ÄÚÈÝ
17£®É½¹ÈÖÐÓÐÈý¿é´óʯͷºÍÒ»¸ù²»¿ÉÉ쳤µÄÇáÖÊÇàÌÙ£¬ÆäʾÒâͼÈçÏ£®Í¼ÖÐA¡¢B¡¢C¡¢D¾ùΪʯͷµÄ±ßÔµµã£¬OΪÇàÌٵĹ̶¨µã£¬h1=1.8m£¬h2=4.0m£¬x1=4.8m£¬x2=8.0m£®¿ªÊ¼Ê±£¬ÖÊÁ¿·Ö±ðΪM=10kgºÍm=2kgµÄ´óСÁ½Ö»µá½ðË¿ºï·Ö±ðλÓÚ×ó±ßºÍÖмäµÄʯͷÉÏ£¬µ±´óºï·¢ÏÖСºï½«Êܵ½É˺¦Ê±£¬Ñ¸ËÙ´Ó×ó±ßʯͷAµãÆðˮƽÌøµ½Öмäʯͷ£¬´óºï±§ÆðСºïÅܵ½Cµã£¬×¥×¡ÇàÌÙµÄ϶˵´µ½ÓÒ±ßʯͷµÄDµã£¬´ËʱËÙ¶ÈÇ¡ºÃΪÁ㣮Ô˶¯¹ý³ÌÖкï×Ó¾ù¿´³ÉÖʵ㣬¿ÕÆø×èÁ¦²»¼Æ£¬ÖØÁ¦¼ÓËÙ¶Èg=10m/s2£¬Ç󣺣¨1£©´óºï×ÓˮƽÌøÀëµÄËÙ¶È×îСֵ
£¨2£©ºï×ÓץסÇàÌÙµ´ÆðʱµÄËٶȴóС
£¨3£©µ´Æðʱ£¬ÇàÌÙ¶Ôºï×ÓµÄÀÁ¦´óС£®
·ÖÎö £¨1£©´óºï´ÓAµãµ½Bµã×öƽÅ×Ô˶¯£¬¸ù¾Ý¸ß¶ÈÇó³öÔ˶¯Ê±¼ä£¬ÔÙ¸ù¾ÝˮƽλÒÆÇó³ö´óºïˮƽÌøÀëʱµÄËÙ¶È×îСֵ£®
£¨2£©¸ù¾ÝCµ½Dµã»úеÄÜÊغ㣬ץסµ½´ïDµãµÄËÙ¶ÈΪÁ㣬Çó³öºï×ÓץסÇàÌÙµ´ÆðʱµÄËٶȴóС£®
£¨3£©¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉ£¬Í¨¹ýÊúÖ±·½ÏòÉϵĺÏÁ¦ÌṩÏòÐÄÁ¦Çó³öÀÁ¦µÄ´óС
½â´ð ½â£º£¨1£©Éèºï×Ó´ÓAµãˮƽÌøÀëʱËٶȵÄ×îСֵΪvmin£¬
ºï×ÓÀ뿪Aµã×öƽÅ×Ô˶¯Ê±£¬³õËÙ¶È×îС£¬ºï×Ó×öƽÅ×Ô˶¯£¬
ÔÚÊúÖ±·½ÏòÉÏ£ºh1=$\frac{1}{2}$gt2£¬
ˮƽ·½Ïò£ºx1=vmint£¬
½âµÃ£ºvmin=8m/s£»
£¨2£©ºï×ÓץסÇàÌÙºóµÄÔ˶¯¹ý³ÌÖлúеÄÜÊغ㣬Éèµ´ÆðʱËÙ¶ÈΪvc£¬
´ÓCµ½D¹ý³Ì£¬ÓÉ»úеÄÜÊغ㶨Âɵãº
£¨M+m£©gh2=$\frac{1}{2}$£¨M+m£©vC2£¬
½âµÃ£ºvC=4$\sqrt{5}$m/s
£¨3£©ÉèÀÁ¦ÎªF£¬ÇàÌٵij¤¶ÈΪL£¬¶ÔµÍλµã£¬ÓÉÅ£¶ÙµÚ¶þ¶¨ÂɵÃ
F-£¨M+m£©g=£¨M+m£©$\frac{{v}_{0}^{2}}{L}$
Óɼ¸ºÎ¹Øϵ
$£¨L-{h}_{2}£©^{2}+{{x}_{2}}^{2}={L}^{2}$
µÃ£ºL=10m
½âµÃ£ºF=216N
´ð£º
£¨1£©´óºï´ÓAµãˮƽÌøÀëʱËٶȵÄ×îСֵΪ8m/s£®
£¨2£©ºï×ÓץסÇàÌÙµ´ÆðʱµÄËٶȴóС$4\sqrt{5}$m/s£®
£¨3£©ºï×Óµ´Æðʱ£¬ÇàÌÙ¶Ôºï×ÓµÄÀÁ¦´óСΪ216N£®
µãÆÀ ±¾Ìâ×ۺϿ¼²éÁËƽÅ×Ô˶¯£¬Ô²ÖÜÔ˶¯£¬ÔËÓÃÁË»úеÄÜÊغ㶨ÂÉ¡¢Å£¶ÙµÚ¶þ¶¨ÂÉ£¬×ÛºÏÐÔ½ÏÇ¿£¬ÄѶȲ»´ó£¬Ðè¼ÓÇ¿ÕâÀàÌâÐ͵ÄѵÁ·£®
A£® | Èç¹ûBÔö´ó£¬vm½«±ä´ó | B£® | Èç¹û¦ÁÔö´ó£¬vm½«±ä´ó | ||
C£® | Èç¹ûRÔö´ó£¬vm½«±ä´ó | D£® | Èç¹ûmÔö´ó£¬vm½«±ä´ó |
A£® | ²»ÄÜ¿´×÷ÖʵãµÄÁ½ÎïÌå¼äÒ²²»´æÔÚÏ໥×÷ÓõÄÒýÁ¦ | |
B£® | ÈκÎÁ½ÎïÌå¼äµÄÒýÁ¦²Å¶¼ÄÜÖ±½ÓÓÃF=$\frac{G{m}_{1}{m}_{2}}{{r}^{2}}$¼ÆËã | |
C£® | ÓÉF=$\frac{G{m}_{1}{m}_{2}}{{r}^{2}}$Öª£¬Á½ÎïÌå¼ä¾àÀërÇ÷½üÓÚ0ʱ£¬ËüÃǼäµÄÒýÁ¦ÎÞÇî´ó | |
D£® | ÍòÓÐÒýÁ¦³£Á¿GµÄÊýÖµÊ×ÏÈÊÇÓÉ¿¨ÎĵÏÐí²â³öÀ´µÄ |
A£® | ºÏÉÏ¿ª¹Ø£¬aÏÈÁÁ£¬bºóÁÁ£»Îȶ¨ºóa¡¢bÒ»ÑùÁÁ | |
B£® | ºÏÉÏ¿ª¹Ø£¬bÏÈÁÁ£¬aºóÁÁ£»Îȶ¨ºób±Èa¸üÁÁһЩ | |
C£® | ¶Ï¿ª¿ª¹Ø£¬a¡¢b¶¼²»»áÁ¢¼´Ï¨Ãð¶øÊÇÖð½¥Ï¨Ãð | |
D£® | ¶Ï¿ª¿ª¹Ø£¬bÖð½¥Ï¨Ãð¡¢aÏȱäµÃ¸üÁÁºóÔÙÓëbͬʱϨÃð |
A£® | A±ÈBÏÈÁÁ£¬È»ºóAϨÃð | |
B£® | B±ÈAÏÈÁÁ£¬È»ºóBÖ𽥱䰵£¬AÖð½¥±äÁÁ | |
C£® | ABÒ»ÆëÁÁ£¬È»ºóAϨÃð | |
D£® | A¡¢BÒ»ÆëÁÁ£®È»ºóAÖð½¥±äÁÁ£®BµÄÁÁ¶È²»±ä |
A£® | 20m | B£® | 30m | ||
C£® | 25m | D£® | ³õËÙ¶Èδ֪£¬ÎÞ·¨È·¶¨ |