ÌâÄ¿ÄÚÈÝ
3£®ÈçͼËùʾ£¬Ô²ÖùÐÎÈÝÆ÷±»»îÈû·Ö³É¼×¡¢ÒÒÁ½¸öÆøÊÒ£¬¼×ÆøÊÒÓëUÐβ£Á§¹ÜÏàÁ¬£¬²£Á§¹ÜÖÐÓÐÒ»¶ÎË®ÒøÖù£¬¿ªÊ¼Ê±£¬Á½ÆøÊÒÖзâ±Õ×ÅͬÖÖÀíÏëÆøÌ壬ÇÒÁ½ÆøÊÒµÄÌå»ý¾ùΪV£»UÐιܵÄÓÒ¹ÜÖеÄˮƽҺÃæ±È×ó¹ÜÖиßh£¬Ë®ÒøµÄÃܶÈΪ¦Ñ£¬ÖØÁ¦¼ÓËÙ¶ÈΪg£¬»îÈûµÄÖÊÁ¿Îªm£¬»îÈûµÄ½ØÃæ»ýΪS£¬»îÈûÓëÈÝÆ÷ÄÚ±ÚÎÞ Ä¦²ÁÇÒÃÜ·âÁ¼ºÃ£¬ÈÝÆ÷ºÍ»îÈûµÄÉ¢ÈÈÐÔÄÜÁ¼ºÃ£¬ºöÂÔUÐβ£Á§¹ÜµÄÈÝ»ýÇÒUÐβ£Á§¹Ü×ã¹»³¤£¬´óÆøѹǿµÈÓÚP0£¬Ç󣺣¨I £©Á½ÆøÊÒÖÐÆøÌåµÄѹǿ֮±ÈΪ¶àÉÙ£»
£¨¢ò£©ÈôÏò²£Á§¹Ü×ó¹Ü»ºÂýµ¹ÈëË®Òø£¬Ê¹»îÈûÏòÏÂÒƶ¯£¬½á¹ûÒÒÆøÊÒµÄÌå»ý¼õСΪÔÀ´µÄ$\frac{4}{5}$£®Ôò´Ëʱ²£Á§¹ÜÁ½±ßË®ÒøÃæµÄ¸ß¶È²îΪ¶àÉÙ£®
·ÖÎö £¨¢ñ£©ÏÈÇó³ö¼×ÒÒÆøÊÒÖÐÆøÌåµÄѹǿ£¬ÔÙÇó±ÈÖµ£»
£¨¢ò£©¶ÔÒÒÆøÊÒÆøÌåÑо¿£¬¸ù¾Ý²£Òâ¶ú¶¨ÂÉÇó³öĩ״̬µÄѹǿ£¬ÔÙ½áºÏË®ÒøÖù¸ß¶È²î¼°¼×ÒÒÆøÊÒѹǿ¹Øϵ¼´¿ÉÇó½â£»
½â´ð ½â£º£¨¢ñ£©¼×ÆøÊÒÖÐÆøÌåѹǿ P1=P0-pgh
ÒÒÆøÊÒÖÐÆøÌåµÄѹǿ ${p}_{2}^{\;}={p}_{1}^{\;}+\frac{mg}{S}$
Òò´Ë¼×¡¢ÒÒÆøÊÒÖÐÆøÌåµÄѹǿ֮±ÈΪ$\frac{{p}_{1}^{\;}}{{p}_{2}^{\;}}=\frac{{p}_{0}^{\;}S-¦ÑghS}{{p}_{0}^{\;}S-¦ÑghS+mg}$
£¨¢ò£©¶ÔÒÒÆøÊÒÑо¿£¬ÆøÌå·¢ÉúµÄÊǵÈα仯£¬Ôò
${p}_{2}^{\;}V={p}_{3}^{\;}¡Á\frac{4}{5}V$
½â£®${p}_{3}^{\;}=\frac{5}{4}{p}_{2}^{\;}=\frac{5}{4}£¨{p}_{0}^{\;}-¦Ñgh+\frac{mg}{S}£©$
Éè´Ëʱ×ó²àË®ÒøÖù±ÈÓÒ²à¸ß H
Ôò${p}_{3}^{\;}=¦ÑgH+{p}_{0}^{\;}+\frac{mg}{S}$
½âµÃ£º$H=\frac{{p}_{0}^{\;}S+mg}{4¦ÑgS}-\frac{5}{4}h$
´ð£º£¨I £©Á½ÆøÊÒÖÐÆøÌåµÄѹǿ֮±ÈΪ$\frac{{p}_{0}^{\;}S-¦ÑghS}{{P}_{0}^{\;}S-¦ÑghS+mg}$£»
£¨¢ò£©ÈôÏò²£Á§¹Ü×ó¹Ü»ºÂýµ¹ÈëË®Òø£¬Ê¹»îÈûÏòÏÂÒƶ¯£¬½á¹ûÒÒÆøÊÒµÄÌå»ý¼õСΪÔÀ´µÄ$\frac{4}{5}$£®Ôò´Ëʱ²£Á§¹ÜÁ½±ßË®ÒøÃæµÄ¸ß¶È²îΪ$\frac{{p}_{0}^{\;}S+mg}{4¦ÑgS}$-$\frac{5}{4}h$
µãÆÀ ±¾Ì⿼²éÆøÌåʵÑ鶨ÂɵÄÓ¦ÓÃÒÔ¼°ÆøÌåѹǿµÄ¼ÆË㣬ҪעÒâÕýÈ·Ñ¡ÔñÑо¿¶ÔÏ󣬷ÖÎöºÃ¶ÔÓ¦µÄ״̬£¬ÔÙÑ¡ÔñÕýÈ·µÄÎïÀí¹æÂÉÇó½â¼´¿É
A£® | 7.0m/s | B£® | 7.7m/s | C£® | 8.5m/s | D£® | 10.0m/s |
A£® | 4£º3 | B£® | 3£º1 | C£® | 5£º3 | D£® | 5£º2 |
A£® | ²¼ÀÊÔ˶¯ÊÇÓÃÏÔ΢¾µ¹Û²ìµ½µÄ·Ö×ÓµÄÔ˶¯ | |
B£® | Ò»¶¨ÖÊÁ¿µÄÀíÏëÆøÌ壬ÔÚÌå»ý²»±äµÄÇé¿öÏÂζÈÉý¸ßѹǿ¿ÉÄܲ»±ä | |
C£® | ÆøÌå¶ÔÍâ×ö¹¦£¬ÆøÌåµÄÄÚÄÜÓпÉÄܱ£³Ö²»±ä | |
D£® | ÈÈÁ¿¿ÉÄÜ×Ô·¢µØ´ÓµÍÎÂÎïÌå´«µÝµ½¸ßÎÂÎïÌå |
A£® | Èç¹û½«MN¼äµÄ¾øÔµ½éÖʳé³ö¡¢´øµçÓ͵ÎP½«ÏòÉÏÒƶ¯ | |
B£® | Èç¹û½«MN¼äµÄ¾øÔµ½éÖʳé³ö¡¢U1Ôö´ó£¬U2Ôö´ó | |
C£® | Èç¹û½«N°åÏÂÒÆ£¬Q1Ôö´ó£¬Q2¼õС | |
D£® | Èç¹û½«N°åÏÂÒÆ£¬U1¼õС£¬U2Ôö´ó |
A£® | ¼ÓËÙ¶ÈΪÁã | B£® | ÏòÐÄÁ¦ÎªÁã | ||
C£® | ²»ÊܵØÇòÒýÁ¦×÷Óà | D£® | ËùÊܵØÇòÒýÁ¦ÌṩÏòÐÄÁ¦ |