ÌâÄ¿ÄÚÈÝ
4£®ÈçͼËùʾ£¬Æ½ÐÐÇãб¹â»¬µ¼¹ìÓë×ã¹»³¤µÄƽÐÐˮƽ¹â»¬µ¼¹ìƽ»¬Á¬½Ó£¬µ¼¹ìµç×è²»¼Æ£®ÖÊÁ¿·Ö±ðΪmºÍ$\frac{1}{2}$mµÄ½ðÊô°ôbºÍc¾²Ö¹·ÅÔÚˮƽµ¼¹ìÉÏ£¬b¡¢cÁ½°ô¾ùÓëµ¼¹ì´¹Ö±£®Í¼ÖÐdeÐéÏßÒÔÓÒÓз¶Î§×ã¹»´ó¡¢·½ÏòÊúÖ±ÏòÉϵÄÔÈÇ¿´Å³¡£®ÖÊÁ¿ÎªmµÄ¾øÔµ°ôa´¹Ö±ÓÚÇãбµ¼¹ì¾²Ö¹ÊÍ·Å£¬ÊÍ·ÅλÖÃÓëˮƽµ¼¹ìµÄ¸ß¶È²îΪh£®ÒÑÖª¾øÔµ°ôa»¬µ½Ë®Æ½µ¼¹ìÉÏÓë½ðÊô°ôb·¢Éúµ¯ÐÔÕýÅö£¬½ðÊô°ôb½øÈë´Å³¡ºóʼÖÕδÓë½ðÊô°ôc·¢ÉúÅöײ£®ÖØÁ¦¼ÓËÙ¶ÈΪg£®Ç󣺣¨1£©¾øÔµ°ôaÓë½ðÊô°ôb·¢Éúµ¯ÐÔÕýÅöºó·ÖÀëʱÁ½°ôµÄËٶȣ»
£¨2£©Á½½ðÊô°ôb¡¢cÉÏ×îÖÕ²úÉúµÄ×ܽ¹¶úÈÈ£»
£¨3£©Çó½ðÊô°ôb½øÈë´Å³¡ºó£¬Æä¼ÓËÙ¶ÈΪÆä×î´ó¼ÓËٶȵÄÒ»°ëʱµÄËٶȣ®
·ÖÎö £¨1£©a°ôÑØ×ÅбÃæÏ»¬¹ý³ÌÖ»ÓÐÖØÁ¦×ö¹¦£¬¸ù¾Ý»úеÄÜÊغ㶨ÂÉÁÐʽÇó³öa°ô»¬µ½Ð±Ãæµ×¶ËʱµÄËٶȣ»°ôaÓë½ðÊô°ôb·¢Éúµ¯ÐÔÕýÅö£¬¸ù¾Ý¶¯Á¿Êغ㶨ÂɺͻúеÄÜÊغ㶨ÂÉÁÐʽ£¬¿ÉÇóµÃ·ÖÀëʱÁ½°ôµÄËٶȣ»
£¨2£©b°ô»ñµÃËٶȺóÏòÓÒ×öÇиî´Å¸ÐÏßÔ˶¯£¬²úÉú¸ÐÓ¦µçÁ÷£¬ÔÚ°²ÅàÁ¦×÷ÓÃÏ£¬b°ô×ö¼õËÙÔ˶¯£¬c°ô×ö¼ÓËÙÔ˶¯£¬×îÖÕbcÁ½°ôÒÔÏàͬµÄËÙ¶ÈÔÈËÙÔ˶¯£¬ÓÉÓÚϵͳµÄºÏÍâÁ¦ÎªÁ㣬×ñÊض¯Á¿Êغ㶨Âɸù¾Ý¶¯Á¿Êغ㶨ÂÉÁÐʽÇó½â¹²Í¬Ëٶȣ¬È»ºó½áºÏ¹¦ÄܹØϵÇó½â²úÉúµÄ×ܽ¹¶úÈÈ£»
£¨3£©b°ô¸Õ½ø´Å³¡µÄ¼ÓËÙ¶È×î´ó£®µ±b°ô¼ÓËÙ¶ÈΪ×î´óÖµµÄÒ»°ëʱ£¬¸ù¾ÝϵͳµÄ¶¯Á¿ÊغãºÍËٶȹØϵÇó½â£®
½â´ð ½â£º£¨1£©a°ôÑØ×ÅбÃæÏ»¬µÄ¹ý³Ì»úеÄÜÊغ㣬ÔòÓÐ
mgh=$\frac{1}{2}$mv02£®
a°ôÓëb°ô·¢Éúµ¯ÐÔÅöײ£¬È¡ÏòÓÒΪÕý·½Ïò£¬Óɶ¯Á¿Êغ㶨ÂɵÃ
mv0=mv1+mv2
¸ù¾Ý»úеÄÜÊغãÓÐ $\frac{1}{2}$mv02=$\frac{1}{2}$mv12+$\frac{1}{2}$mv22
½â³öÅöºóa¡¢bÁ½°ôµÄËٶȷֱðΪ v1=0£¬v2=v0=$\sqrt{2gh}$
£¨2£©×îÖÕb¡¢cÒÔÏàͬµÄËÙ¶ÈÔÈËÙÔ˶¯£®É蹲ͬËÙ¶ÈΪv£®È¡ÏòÓÒΪÕý·½Ïò£¬¸ù¾Ý¶¯Á¿Êغ㶨ÂɵÃ
mv2=£¨m+$\frac{m}{2}$£©v
ÓÉÄÜÁ¿ÊغãµÃ $\frac{1}{2}$mv22=$\frac{1}{2}£¨m+\frac{m}{2}£©{v}^{2}$+Q
½â³ö Q=$\frac{1}{3}$mgh
£¨3£©b°ô¸Õ½ø´Å³¡µÄ¼ÓËÙ¶È×î´ó£®Óɶ¯Á¿ÊغãµÃ mv2=mv2¡ä+$\frac{m}{2}$v3¡ä
¸ù¾ÝF°²=BIL=B$\frac{E}{R}$L£¬Öªµ±b°ô¼ÓËÙ¶ÈΪ×î´óÖµµÄÒ»°ëʱÓÐ v2=2£¨v2¡ä-v3¡ä£©
ÁªÁ¢µÃ v2¡ä=$\frac{5}{6}{v}_{2}$=$\frac{5}{6}\sqrt{2gh}$
´ð£º
£¨1£©¾øÔµ°ôaÓë½ðÊô°ôb·¢Éúµ¯ÐÔÕýÅöºó·ÖÀëʱÁ½°ôµÄËٶȷֱðΪ0ºÍ$\sqrt{2gh}$£»
£¨2£©Á½½ðÊô°ôb¡¢cÉÏ×îÖÕ²úÉúµÄ×ܽ¹¶úÈÈÊÇ$\frac{1}{3}$mgh£»
£¨3£©½ðÊô°ôb½øÈë´Å³¡ºó£¬Æä¼ÓËÙ¶ÈΪÆä×î´ó¼ÓËٶȵÄÒ»°ëʱµÄËÙ¶ÈÊÇ$\frac{5}{6}\sqrt{2gh}$£®
µãÆÀ ±¾ÌâÊǵ¼¹ìÎÊÌ⣬¹Ø¼üÊÇÕÆÎÕ¶¯Á¿ÊغãµÄÌõ¼þ£¬ÅжÏbcϵͳµÄ¶¯Á¿Êغ㣬½áºÏ¶¯Á¿Êغ㶨ÂɺÍÄÜÁ¿Êغ㶨ÂɽøÐÐÑо¿£®
A£® | ÕÕƬÉÏСÇòAËù´¦µÄλÖ㬲»ÊÇÿ¸öСÇòµÄÊͷŵã | |
B£® | CµãСÇòËÙ¶ÈÊÇA¡¢DµãСÇòËÙ¶ÈÖ®ºÍµÄÒ»°ë | |
C£® | BµãСÇòµÄËٶȴóСΪ1.5 m/s | |
D£® | ËùÓÐСÇòµÄ¼ÓËٶȴóСΪ5 m/s2 |
A£® | aµãºÍbµãµÄµç³¡Ç¿¶ÈÏàͬ | |
B£® | c¡¢dÁ½µãµçÊƲî´óÓÚ0 | |
C£® | ¸ºµçºÉ´ÓaµãÒƵ½cµã£¬µç³¡Á¦×ö¸º¹¦ | |
D£® | ÕýµçºÉ´ÓeµãÑØͼÖÐÐéÏßÒƵ½fµãµçÊÆÄÜÏȼõСºóÔö´ó |
A£® | ¹â×ÓaµÄÄÜÁ¿´óÓÚ¹â×ÓbµÄÄÜÁ¿ | |
B£® | ¹â×ÓaµÄ²¨³¤´óÓÚ¹â×ÓbµÄ²¨³¤ | |
C£® | ¹â×ÓaµÄƵÂÊ´óÓÚ¹â×ÓbµÄƵÂÊ | |
D£® | ÔÚÕæ¿ÕÖйâ×ÓaµÄ´«²¥ËٶȴóÓÚ¹â×ÓbµÄ´«²¥ËÙ¶È |
A£® | ±¥ºÍÆøѹÓëÈÈÁ¦Ñ§Î¶ȳÉÕý±È | |
B£® | Ò»¶¨Á¿µÄÀíÏëÆøÌåÔÚµÈÎÂÅòÕ͹ý³ÌÖÐÎüÊÕµÄÈÈÁ¿µÈÓÚ¶ÔÍâ×öµÄ¹¦£¬²¢²»Î¥·´ÈÈÁ¦Ñ§µÚ¶þ¶¨ÂÉ | |
C£® | µ±·Ö×Ó¼äµÄÒýÁ¦Óë³âÁ¦Æ½ºâʱ£¬·Ö×ÓÁ¦Ò»¶¨ÎªÁ㣬·Ö×ÓÊÆÄÜÒ»¶¨×îС | |
D£® | ÆøÌåζÈÔ½¸ß£¬ÆøÌå·Ö×ÓÔ˶¯Ô½¾çÁÒ¡¢ÈÝÆ÷±ÚÊܵ½µÄ³å»÷Á¦Ô½´ó¡¢ÆøÌåµÄѹǿԽ´ó | |
E£® | ÔÚÈκÎ×ÔÈ»¹ý³ÌÖУ¬Ò»¸ö¹ÂÁ¢ÏµÍ³ÖеÄ×Üìز»»á¼õÉÙ |
A£® | B¡¢CÁ½µãÖ®¼äµÄ¾àÀëΪ200 m | |
B£® | BC ¶Î×öÔȱäËÙÔ˶¯µÄ¼ÓËٶȴóСΪ4 m/s2 | |
C£® | AB ¶ÎÔÈËÙÔ˶¯ËùÓÃʱ¼äΪ10 s | |
D£® | AC ¶ÎËù¾ÀúµÄʱ¼äΪ25 s |
A£® | $m{g_0}{R^2}£¨{\frac{1}{R_2}-\frac{1}{R_1}}£©$ | B£® | $mg{R^2}£¨{\frac{1}{R_2}-\frac{1}{R_1}}£©$ | ||
C£® | $\frac{{mg{R^2}}}{2}£¨{\frac{1}{R_2}-\frac{1}{R_1}}£©$ | D£® | $\frac{{m{g_0}{R^2}}}{2}£¨{\frac{1}{R_2}-\frac{1}{R_1}}£©$ |
A£® | µ±·Ö×Ó¼äµÄÒýÁ¦Óë³âÁ¦Æ½ºâʱ£¬·Ö×ÓÊÆÄÜ×î´ó | |
B£® | ÓÉìصĶ¨Òå¿ÉÖª£¬ìؽϴóµÄºê¹Û״̬¾ÍÊÇÎÞÐò³Ì¶ÈºÜ´óµÄºê¹Û״̬£¬Ò²¾ÍÊdzöÏÖ¸ÅÂʽϴóµÄºê¹Û״̬ | |
C£® | ÒºÌåµÄ±¥ºÍÆûѹÓë±¥ºÍÆûµÄÌå»ýÓÐ¹Ø | |
D£® | ÈôÒ»¶¨ÖÊÁ¿µÄÀíÏëÆøÌ屻ѹËõÇÒÎüÊÕÈÈÁ¿£¬Ôòѹǿһ¶¨Ôö´ó | |
E£® | ÈôÒ»¶¨ÖÊÁ¿µÄÀíÏëÆøÌå·Ö×Óƽ¾ù¶¯ÄܼõС£¬ÇÒÍâ½ç¶ÔÆøÌå×ö¹¦£¬ÔòÆøÌåÒ»¶¨·ÅÈÈ |