Question

8£®ÈçͼËùʾ£¬ABCDÊÇÓÉÁ½²¿·Ö¹â»¬¹ìµÀƽ»¬Á¬½ÓÔÚÒ»Æð×é³ÉµÄ£¬ABΪˮƽ¹ìµÀ£¬BCDÊǰ뾶ΪRµÄ°ëÔ²»¡¹ìµÀ£¬R=0.6m£®ÖÊÁ¿ÎªM=0.99kgµÄСÎï¿é£¬¾²Ö¹ÔÚAB¹ìµÀÉÏ£¬Ò»¿ÅÖÊÁ¿Îªm=0.01kg×Óµ¯Ë®Æ½ÉäÈëÎï¿éµ«Î´´©³ö£¬Îï¿éÓë×Óµ¯Ò»ÆðÔ˶¯£¬Ç¡ºÃÄÜͨ¹ýDµã·É³ö£®È¡ÖØÁ¦¼ÓËÙ¶Èg=10m/s²£¬Çó£º
£¨1£©Îï¿éÓë×Óµ¯Ò»Æð¸Õ»¬ÉÏÔ²»¡¹ìµÀBµãµÄËٶȣ»
£¨2£©×Óµ¯»÷ÖÐÎï¿éÇ°µÄËٶȣ»
£¨3£©ÏµÍ³ËðʧµÄ»úеÄÜ£®

Answer 1

·ÖÎö £¨1£©ÓÉÅ£¶ÙµÚ¶þ¶¨ÂÉÓë»úеÄÜÊغ㶨ÂÉ¿ÉÒÔÇó³öBµÄËٶȣ®
£¨2£©×Óµ¯»÷ÖÐľ¿é¹ý³Ìϵͳ¶¯Á¿Êغ㣬Óɶ¯Á¿Êغ㶨ÂÉ¿ÉÒÔÇó³ö×Óµ¯µÄ³õËٶȣ®
£¨3£©ÓÉÄÜÁ¿Êغ㶨ÂÉ¿ÉÒÔÇó³öËðʧµÄ»úеÄÜ£®

½â´ð ½â£º£¨1£©ÓÉÎï¿éÓë×Óµ¯Ò»ÆðÇ¡ÄÜͨ¹ý¹ìµÀ×î¸ßµãD£¬
ÓÉÅ£¶ÙµÚ¶þ¶¨Âɵãº$£¨M+m£©g=£¨M+m£©\frac{v_D^2}{2R}$£¬
ÎïÌåÓë×Óµ¯×é³ÉµÄϵͳ»úеÄÜÊغ㣬
ÓÉ»úеÄÜÊغ㶨Âɵãº$\frac{1}{2}$£¨M+m£©v_D²+£¨M+m£©g•2R=$\frac{1}{2}$£¨M+m£©v_B²£¬
´úÈëÊý¾Ý½âµÃ£ºv_B=6m/s£»
£¨2£©ÏµÍ³¶¯Á¿Êغ㣬ÒÔÏòÓÒΪÕý·½Ïò£¬
Óɶ¯Á¿Êغ㶨Âɵãºmv=£¨M+m£©v_B£¬
´úÈëÊý¾Ý½âµÃ£ºv=600m/s£»
£¨3£©ÓÉÄÜÁ¿Êغ㶨Âɵãº
¡÷E=$\frac{1}{2}$mv²-$\frac{1}{2}$£¨M+m£©v_B²£¬
´úÈëÊý¾Ý½âµÃ£º¡÷E=1782J£»
´ð£º£¨1£©Îï¿éÓë×Óµ¯Ò»Æð¸Õ»¬ÉÏÔ²»¡¹ìµÀBµãµÄËÙ¶ÈΪ6m/s£»
£¨2£©×Óµ¯»÷ÖÐÎï¿éÇ°µÄËÙ¶ÈΪ600m/s£»
£¨3£©ÏµÍ³ËðʧµÄ»úеÄÜΪ1782J£®

µãÆÀ ±¾Ì⿼²éÁËÇóËٶȡ¢ËðʧµÄ»úеÄÜÎÊÌ⣬·ÖÎöÇå³þÎïÌåµÄÔ˶¯¹ý³Ì£¬Ó¦ÓÃÅ£¶ÙµÚ¶þ¶¨ÂÉ¡¢»úеÄÜÊغ㶨ÂÉ¡¢¶¯Á¿Êغ㶨ÂÉÓëÄÜÁ¿Êغ㶨Âɼ´¿ÉÕýÈ·½âÌ⣮