Question

5£®Ä³Ñ§Ï°Ð¡×éµÄͬѧÏëÒªÑéÖ¤¡°¶¯Äܶ¨Àí¡±£¬ËûÃÇÔÚʵÑéÊÒ×é×°ÁËÒ»Ì×Èçͼ1×°Öã¬ÁíÍ⻹Óн»Á÷µçÔ´¡¢µ¼Ïß¡¢¸´Ð´Ö½¶¼Ã»»­³öÀ´£®Èç¹ûÒªÍê³É¸ÃÏîʵÑ飬Ôò£º
£¨1£©»¹ÐèÒªµÄʵÑéÆ÷²ÄÊÇBD
A£®Ãë±í     B£®¿Ì¶È³ß    C£®µ¯»É³Ó       D£®Ììƽ
£¨2£©½øÐÐʵÑé²Ù×÷ʱ£¬Ê×ÏÈÒª×öµÄÖØÒª²½ÖèÊÇƽºâĦ²ÁÁ¦£®

£¨3£©ÔÚ£¨2£©µÄ»ù´¡ÉÏ£¬Ä³Í¬Ñ§ÓÃÌìƽ³Æ³öС³µµÄÖÊÁ¿M£¬Ëù¹Ò¹³ÂëµÄ×ÜÖÊÁ¿Îªm£®ÎªÁ˱£Ö¤Ð¡³µÊܵ½µÄºÏÁ¦Óë¹³ÂëµÄ×ÜÖØÁ¦´óС»ù±¾ÏàµÈ£¬¹³ÂëµÄ×ÜÖÊÁ¿mÓ¦Âú×ãµÄʵÑéÌõ¼þÊÇm?M£®
£¨4£©ÊµÑéʱÊÍ·ÅС³µÈù³Âë´ø×ÅС³µ¼ÓËÙÔ˶¯£¬Óôòµã¼ÆʱÆ÷£¨ÏàÁÚÁ½¸öµãµÄʱ¼ä¼ä¸ôΪT£©¼Ç¼ÆäÔ˶¯Çé¿öÈçͼ2Ö½´øËùʾ£¬Ö½´øÉÏ¿ªÊ¼µÄһЩµã½ÏÄ£ºýδ»­³ö£¬ÏÖ²âµÃOµ½Eµã¼äµÄ³¤ÎªL£¬Dµ½Fµã¼äµÄ³¤ÎªS£¬ÔòEµãËٶȴóСΪ$\frac{S}{2T}$£®ÈôÈ¡OµãµÄËÙ¶ÈΪv₁¡¢EµãËÙ¶ÈΪv₂ÄÇô±¾ÊµÑé×îÖÕÒªÑéÖ¤µÄÊýѧ±í´ïʽΪmgL=$\frac{1}{2}$Mv₂²-$\frac{1}{2}$Mv₁²£®

Answer 1

·ÖÎö £¨1£©¸ù¾ÝʵÑéµÄÔ­ÀíÈ·¶¨ËùÐè²âÁ¿µÄÎïÀíÁ¿£¬´Ó¶øÈ·¶¨»¹ÐèÒªµÄÆ÷²Ä£»
£¨2¡¢3£©ÎªÁËʹС³µËùÊܵĺÏÁ¦µÈÓÚÉþ×ÓµÄÀ­Á¦£¬ÊµÑéǰӦƽºâĦ²ÁÁ¦£¬ÎªÁËʹ¹³ÂëµÄÖØÁ¦µÈÓÚÉþ×ÓµÄÀ­Á¦£¬ÐèÒªÂú×ãС³µµÄÖÊÁ¿Ô¶Ô¶´óÓÚ¹³ÂëµÄÖÊÁ¿£»
£¨4£©¸ù¾Ýij¶Îʱ¼äÄÚµÄƽ¾ùËٶȵÈÓÚÖмäʱ¿ÌµÄ˲ʱËÙ¶ÈÇó³öEµãµÄËٶȣ¬½áºÏºÏÁ¦×ö¹¦µÈÓÚ¶¯Äܵı仯Á¿µÃ³öÑéÖ¤µÄÊýѧ±í´ïʽ£®

½â´ð ½â£º£¨1£©ÊµÑéÑéÖ¤¶¯Äܶ¨Àí£¬¼´ÑéÖ¤ºÏÁ¦¹¦Ó붯Äܱ仯Á¿µÄ¹Øϵ£¬ÐèÒª²âÁ¿Ð¡³µËùÊܵĺÏÁ¦£¬ÔòÐèÒªÌìƽ²âÁ¿¹³ÂëµÄÖÊÁ¿£¬ÒÔ¼°Ð¡³µµÄÖÊÁ¿£¬Óÿ̶ȳ߲â³öµã¼£¼äµÄ¾àÀ룬´Ó¶ø¼ÆËã³öËٶȵĴóС£¬µÃ³ö¶¯Äܵı仯Á¿£®¹ÊÑ¡£ºBD£®
£¨2£©ÊµÑéÖÐÈÏΪÉþ×ÓµÄÀ­Á¦µÈÓÚС³µµÄºÏÁ¦£¬ÔòÊ×ÏÈÒª×öµÄÖØÒª²½ÖèÊÇƽºâĦ²ÁÁ¦£®
£¨3£©¶ÔÕûÌå·ÖÎö£¬ÓУºa=$\frac{mg}{M+m}$£¬¸ôÀë¶ÔС³µ·ÖÎö£¬F=Ma=$\frac{Mmg}{M+m}=\frac{mg}{1+\frac{m}{M}}$£¬Á˱£Ö¤Ð¡³µÊܵ½µÄºÏÁ¦Óë¹³ÂëµÄ×ÜÖØÁ¦´óС»ù±¾ÏàµÈ£¬¹³ÂëµÄ×ÜÖÊÁ¿mÓ¦Âú×ãm?M£®
£¨4£©EµãµÄËٶȵÈÓÚDF¶ÎµÄƽ¾ùËٶȣ¬Ôò${v}_{E}=\frac{S}{2T}$£®
ºÏÁ¦×ö¹¦ÎªmgL£¬¶¯Äܵı仯Á¿Îª$\frac{1}{2}$Mv₂²-$\frac{1}{2}$Mv₁²£¬×îÖÕÒªÑéÖ¤µÄÊýѧ±í´ïʽΪmgL=$\frac{1}{2}$Mv₂²-$\frac{1}{2}$Mv₁²£®
¹Ê´ð°¸Îª£º£¨1£©BD£¬£¨2£©Æ½ºâĦ²ÁÁ¦£¬£¨3£©m?M£¬£¨4£©$\frac{S}{2T}$£¬mgL=$\frac{1}{2}$Mv₂²-$\frac{1}{2}$Mv₁²

µãÆÀ ½â¾ö±¾ÌâµÄ¹Ø¼üÖªµÀʵÑéµÄÔ­Àí£¬ÕÆÎÕʵÑéÖеÄÁ½¸öÈÏΪ£º1¡¢ÈÏΪÉþ×ÓµÄÀ­Á¦µÈÓÚС³µµÄºÏÁ¦£¬Ç°ÌáÐèƽºâĦ²ÁÁ¦£¬2¡¢ÈÏΪ¹³ÂëµÄÖØÁ¦µÈÓÚÉþ×ÓµÄÀ­Á¦£¬Ç°ÌáÊÇС³µµÄÖÊÁ¿Ô¶Ô¶´óÓÚ¹³ÂëµÄÖÊÁ¿£®