ÌâÄ¿ÄÚÈÝ
15£®ÈçͼËùʾÊÇijͬѧÉè¼ÆµÄÒ»ÖÖ·çÁ¦²â¶¨ÒǵÄÔÀíͼ£¬Ëü¿ÉÒÔͨ¹ýµçÁ÷±íµÄʾÊýÀ´²â¶¨·çÁ¦£®Í¼ÖÐPÊÇÒ»¸öÖØÁ¦G=4NµÄСÇò£¬Ðü¹ÒÔÚÒ»¸ù¾É½ðÊôÏßÏÂÃ棬OΪÐü¹Òµã£¬ABÊÇÒ»¸ùˮƽ·ÅÖᢴÖϸ¾ùÔȵĹ⻬µÄµç×èË¿£¬³¤L=30cm£®µç×èÖµRAB=20¦¸£¬±£»¤µç×èR0=5¦¸£®µç×èË¿¡¢±£»¤µç×è¡¢µçÁ÷±íºÍÐü¹ÒСÇòµÄÒ»²¿·Ö½ðÊôË¿´®ÁªÆðÀ´½ÓÔÚµçѹU=10VµÄµç·ÉÏ£®ÔÚÎÞ·çʱ½ðÊôË¿Óëµç×èË¿A¶Ë½Ó´¥£®OA=10cm£¬µ±Ë®Æ½·çÁ¦Ïò×ó×÷ÓÃÓÚСÇòʱ£¬ÐüÏß½«Æ«¹ýÒ»¶¨µÄ½Ç¶È¦È£®½ðÊôÏßÓëµç×èË¿ÏཻÓÚCµã£¬½Ó´¥Á¼ºÃ£¬½ðÊôÏߵĵç×è²»¼Æ£®ÎÊ£º£¨1£©ÎÞ·çʱµçÁ÷±íµÄʾÊýÊǶà´ó£¿
£¨2£©Ë®Æ½·çÁ¦´ï3Nʱ£¬µçÁ÷±íµÄʾÊýΪ¶à´ó£¿
·ÖÎö £¨1£©ÎÞ·çʱ£¬ÓÉÅ·Ä·¶¨ÂÉÇóµçÁ÷±íµÄʾÊý£®
£¨2£©ÓÉСÇòµÄÊÜÁ¦Æ½ºâ£¬Çó½ðÊô˿ƫתµÄ½Ç¶È¦È£¬µÃµ½BC¼äµÄµç×裬ÔÙÓÉÅ·Ä·¶¨ÂÉÇó½â£®
½â´ð ½â£º£¨1£©ÎÞ·çʱ£¬ÓÉÅ·Ä·¶¨Âɵãº
I=$\frac{U}{{R}_{0}+{R}_{AB}}$=$\frac{10}{5+20}$A=0.4A
¼´µçÁ÷±íµÄʾÊýΪ0.4A£®
£¨2£©Ë®Æ½·çÁ¦ F=3Nʱ£¬ÔòÓÐ tan¦È=$\frac{F}{G}$=$\frac{3}{4}$
ÔòBC=L-OAtan¦È=30cm-10cm¡Á$\frac{3}{4}$=22.5cm
ËùÒÔBC¼äµÄµç×èΪ RBC=$\frac{BC}{L}{R}_{AB}$=$\frac{22.5}{30}¡Á20$¦¸=15¦¸
¹ÊµçÁ÷±íµÄʾÊýΪ I¡ä=$\frac{U}{{R}_{0}+{R}_{BC}}$=$\frac{10}{5+15}$A=0.5A
´ð£º
£¨1£©ÎÞ·çʱµçÁ÷±íµÄʾÊýÊÇ0.4A£®
£¨2£©Ë®Æ½·çÁ¦´ï3Nʱ£¬µçÁ÷±íµÄʾÊýΪ0.5A£®
µãÆÀ ±¾Ìâ½âÌâµÄ¹Ø¼üÊÇÕÒ³öµç×èÓë½Ç¶ÈµÄÊýÁ¿¹ØϵÒÔ¼°·çÁ¦Óë½Ç¶ÈµÄ¹Øϵ£¬ÔÙÓÉÅ·Ä·¶¨Âɽâ´ð£®
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿
5£®Á½¸ö·Ö±ð´øÓеçºÉÁ¿-QºÍ+3QµÄÏàͬ½ðÊôСÇò£¨¾ù¿ÉÊÓΪµãµçºÉ£©£¬¹Ì¶¨ÔÚÏà¾àΪrµÄÁ½´¦£¬ËüÃǼä¿âÂØÁ¦µÄ´óСΪF£¬Á½Ð¡ÇòÏ໥½Ó´¥ºó½«Æä¹Ì¶¨¾àÀë±äΪ$\frac{r}{2}$£¬ÔòÁ½Çò¼ä¿âÂØÁ¦µÄ´óСΪ£¨¡¡¡¡£©
A£® | $\frac{3}{4}$F£¬ÅųâÁ¦ | B£® | $\frac{3}{4}$F£¬ÎüÒýÁ¦ | C£® | $\frac{4}{3}$F£¬ÅųâÁ¦ | D£® | $\frac{4}{3}$F£¬ÎüÒýÁ¦ |
6£®Ä³Í¬Ñ§Ì½¾¿µ¯Á¦ºÍµ¯»ÉÉ쳤µÄ¹Øϵ£¬²¢²âµ¯»ÉµÄ¾¢¶ÈϵÊýk£®×ö·¨ÊÇÏȽ«´ý²âµ¯»ÉµÄÒ»¶Ë¹Ì¶¨ÔÚÌú¼Ų̈ÉÏ£¬È»ºó½«×îС¿Ì¶ÈÊǺÁÃ׵Ŀ̶ȳßÊúÖ±·ÅÔÚµ¯»ÉÒ»²à£¬²¢Ê¹µ¯»ÉÁíÒ»¶ËµÄÖ¸ÕëÇ¡ºÃÂäÔڿ̶ȳßÉÏ£®µ±µ¯»É×ÔȻϴ¹Ê±£¬Ö¸ÕëָʾµÄ¿Ì¶ÈÊýÖµ¼Ç×÷L0£»µ¯»É϶˹ÒÒ»¸ö50gµÄíÀÂëʱ£¬Ö¸ÕëָʾµÄ¿Ì¶ÈÊýÖµ¼Ç×÷L1£»µ¯»É϶˹ÒÁ½¸ö50gµÄíÀÂëʱ£¬Ö¸ÕëָʾµÄ¿Ì¶ÈÊýÖµ¼Ç×÷L2£»¡¹ÒÆ߸ö50gµÄíÀÂëʱ£¬Ö¸ÕëָʾµÄ¿Ì¶ÈÊýÖµ¼Ç×÷L7£®
£¨1£©Ï±í¼Ç¼µÄÊǸÃͬѧÒѲâ³öµÄ6¸öÖµ£¬ÆäÖÐÓÐÁ½¸öÊýÖµÔڼǼʱÓÐÎó£¬ËüÃǵĴú±í·ûºÅ·Ö±ðÊÇL5ºÍL6£®²âÁ¿¼Ç¼±í£º
£¨2£©ÊµÑéÖУ¬L3ºÍL7Á½¸öÖµ»¹Ã»Óвⶨ£¬ÇëÄã¸ù¾ÝÈçͼ½«ÕâÁ½¸ö²âÁ¿ÖµÌîÈë¼Ç¼±íÖУ®
£¨3£©Îª³ä·ÖÀûÓòâÁ¿Êý¾Ý£¬¸Ãͬѧ½«Ëù²âµÃµÄÊýÖµ°´ÈçÏ·½·¨ÖðÒ»Çó²î£¬·Ö±ð¼ÆËã³öÁËÈý¸ö²îÖµ£º
d1=L4-L0=6.90cm£»d2=L5-L1=6.90cm£» d3=L6-L2=7.00cm£»
ÇëÄã¸øµÚËĸö²îÖµ£ºd4=L7-L3=7.20cm£®
£¨4£©¸ù¾ÝÒÔÉϲîÖµ£¬¿ÉÒÔÇó³öÿÔö¼Ó50gíÀÂëµÄµ¯»Éƽ¾ùÉ쳤Á¿¡÷L£®¡÷LÓÃd1¡¢d2¡¢d3¡¢d4±íʾµÄʽ×ÓΪ¡÷L=$\frac{{d}_{1}+{d}_{2}+{d}_{3}+{d}_{4}}{4¡Á4}$£¬´úÈëÊý¾Ý½âµÃ¡÷L=1.75cm£®
£¨5£©¼ÆË㵯»ÉµÄ¾¢¶ÈϵÊýk=28.0N/m£®£¨gÈ¡9.8m/s2£©
£¨1£©Ï±í¼Ç¼µÄÊǸÃͬѧÒѲâ³öµÄ6¸öÖµ£¬ÆäÖÐÓÐÁ½¸öÊýÖµÔڼǼʱÓÐÎó£¬ËüÃǵĴú±í·ûºÅ·Ö±ðÊÇL5ºÍL6£®²âÁ¿¼Ç¼±í£º
´ú±í ·ûºÅ | L0 | L1 | L2 | L3 | L4 | L5 | L6 | L7 |
¿Ì¶ÈÊýÖµ/cm | 1.70 | 3.40 | 5.10 | 8.60 | 10.3 | 12.1 |
£¨3£©Îª³ä·ÖÀûÓòâÁ¿Êý¾Ý£¬¸Ãͬѧ½«Ëù²âµÃµÄÊýÖµ°´ÈçÏ·½·¨ÖðÒ»Çó²î£¬·Ö±ð¼ÆËã³öÁËÈý¸ö²îÖµ£º
d1=L4-L0=6.90cm£»d2=L5-L1=6.90cm£» d3=L6-L2=7.00cm£»
ÇëÄã¸øµÚËĸö²îÖµ£ºd4=L7-L3=7.20cm£®
£¨4£©¸ù¾ÝÒÔÉϲîÖµ£¬¿ÉÒÔÇó³öÿÔö¼Ó50gíÀÂëµÄµ¯»Éƽ¾ùÉ쳤Á¿¡÷L£®¡÷LÓÃd1¡¢d2¡¢d3¡¢d4±íʾµÄʽ×ÓΪ¡÷L=$\frac{{d}_{1}+{d}_{2}+{d}_{3}+{d}_{4}}{4¡Á4}$£¬´úÈëÊý¾Ý½âµÃ¡÷L=1.75cm£®
£¨5£©¼ÆË㵯»ÉµÄ¾¢¶ÈϵÊýk=28.0N/m£®£¨gÈ¡9.8m/s2£©
10£®ÈçͼËùʾÊÇÒ»Ö§ÂÃÐÐÓõġ°Á½ÃæÕ롱ÑÀ¸à£¬¸ÃÑÀ¸àµÄÍâ¿ÇÊÇÓÉÂÁ±¡Æ¤×öµÄ£¬¸ù¾ÝÄãµÄ¹Û²ìºÍÉú»î¾Ñ飬ÏÂÁÐ˵·¨ÕýÈ·µÄÊÇ£¨¡¡¡¡£©
A£® | ÑÀ¸à¸ÇÉϵÄÌõÎÆÊÇΪÁËÃÀ¹Û | |
B£® | ÑÀ¸à±»¼·³öÀ´ÊÇÒòΪÑÀ¸àÊܵ½ÊÖµÄ×÷ÓÃÁ¦ | |
C£® | ¸ÃÑÀ¸àƤ±»¼·Ñ¹ºó·¢ÉúµÄÐαäΪ·Çµ¯ÐÔÐαä | |
D£® | ¼·ÑÀ¸àʱÊÖ¶ÔÑÀ¸àƤµÄ×÷ÓÃÁ¦´óÓÚÑÀ¸àƤ¶ÔÊÖµÄ×÷ÓÃÁ¦ |
7£®Á½¸öÁ¦F1ºÍF2Ö®¼äµÄ¼Ð½ÇΪ¦È£¬Á½¸öÁ¦µÄºÏÁ¦ÎªF£¬ÏÂÁÐ˵·¨ÕýÈ·µÄÊÇ£¨¡¡¡¡£©
A£® | F1ºÍF2Ôö´óʱ£¬ºÏÁ¦FÒ»¶¨Ôö´ó | |
B£® | F1ºÍF2Ôö´óʱ£¬ºÏÁ¦F¿ÉÄܼõС | |
C£® | F1ºÍF2Ò»¶¨£¬¼Ð½Ç¦ÈÔö´ó£¨¦È¡Ü180¡ã£©Ê±£¬ºÏÁ¦FÒ»¶¨Ôö´ó | |
D£® | F1ºÍ¼Ð½Ç¦ÈÒ»¶¨£¨¦È¡Ü180¡ã£©Ê±£¬Ö»ÒªF2Ôö´ó£¬ºÏÁ¦F¾ÍÒ»¶¨Ôö´ó |
4£®ÎïÌåÊܵ½¼¸¸öÍâÁ¦µÄ×÷Óöø×÷ÔÈËÙÖ±ÏßÔ˶¯£¬Èç¹û³·µôÆäÖеÄÒ»¸öÁ¦£¬Ëü¿ÉÄÜ×ö£¨¡¡¡¡£©
A£® | ÔÈËÙÖ±ÏßÔ˶¯ | B£® | ÔȱäËÙÖ±ÏßÔ˶¯ | C£® | ÔÈËÙÔ²ÖÜÔ˶¯ | D£® | ÀàƽÅ×Ô˶¯ |
5£®¡°±Ä¼«¡±ÊÇÒ»Ïî´Ì¼¤µÄ¼«ÏÞÔ˶¯£¬ÖÊÁ¿ÎªmµÄÔ˶¯Ô±½«Ò»¶Ë¹Ì¶¨µÄ³¤µ¯ÐÔÉþ°óÔÚõ׹ؽڴ¦£¬´Ó¼¸Ê®Ã׸ߴ¦ÌøÏ£®ÔÚij´Î±Ä¼«ÖУ¬µ¯ÐÔÉþµ¯Á¦FµÄ´óСËæʱ¼ätµÄ±ä»¯Í¼ÏóÈçͼËùʾ£¬½«±Ä¼«¹ý³Ì½üËÆΪÔÚÊúÖ±·½ÏòµÄÔ˶¯£¬µ¯ÐÔÉþ´¦ÓÚµ¯ÐÔÏÞ¶ÈÄÚ£¬¿ÕÆø×èÁ¦²»¼Æ£®ÏÂÁÐ˵·¨ÕýÈ·µÄÊÇ£¨¡¡¡¡£©
A£® | t1¡«t2ʱ¼äÄÚÔ˶¯Ô±´¦ÓÚʧÖØ״̬ | |
B£® | t2¡«t4ʱ¼äÄÚÔ˶¯Ô±µÄ»úеÄÜÏȼõÉÙºóÔö´ó | |
C£® | t3ʱ¿ÌÔ˶¯Ô±µÄ¼ÓËÙ¶ÈΪÁã | |
D£® | t4ʱ¿ÌÔ˶¯Ô±¾ßÓÐÏòÉϵÄ×î´óËÙ¶È |