Question

12£®ÈçͼËùʾΪÀûÓÃÆøµæµ¼¹ì£¨»¬¿éÔڸõ¼¹ìÉÏÔ˶¯Ê±ËùÊÜ×èÁ¦¿ÉºöÂÔ£©¡°ÑéÖ¤»úеÄÜÊغ㶨ÂÉ¡±µÄʵÑé×°Öã¬ÊµÑé²Ù×÷²½ÖèÈçÏ£º
A£®½«Æøµæµ¼¹ì·ÅÔÚˮƽ×ÀÃæÉÏ£¬×ÀÃæ¸ß¶È²»µÍÓÚ1m£¬½«µ¼¹ìµ÷ÖÁˮƽ£®
B£®²â³öµ²¹âÌõµÄ¿í¶ÈlºÍÁ½¹âµçÃÅÖÐÐÄÖ®¼äµÄ¾àÀës
C£®½«»¬¿éÒÆÖÁ¹âµçÃÅ1×ó²àij´¦£¬´ýíÀÂë¾²Ö¹²»¶¯Ê±£¬ÊÍ·Å»¬¿é£¬ÒªÇóíÀÂëÂäµØÇ°µ²¹âÌõÒÑͨ¹ý¹âµçÃÅ2£®
D£®¶Á³ö»¬¿éͨ¹ý¹âµçÃÅ1ºÍ¹âµçÃÅ2ËùÓõÄʱ¼ä¡÷t₁ºÍ¡÷t₂£®
E£®ÓÃÌìƽ³Æ³ö»¬¿éºÍµ²¹âÌõµÄ×ÜÖÊÁ¿M£¬ÔٳƳöÍÐÅ̺ÍíÀÂëµÄ×ÜÖÊÁ¿m£®
¸ù¾ÝʵÑé²½Öè»ã×ܲâµÃµÄÎïÀíÁ¿Íê³ÉÏÂÁпոñ£º
£¨1£©»¬¿éͨ¹ý¹âµçÃÅ1ºÍ¹âµçÃÅ2ʱ£¬¿ÉÒÔÈ·¶¨ÏµÍ³£¨°üÀ¨»¬¿é¡¢µ²¹âÌõ¡¢ÍÐÅ̺ÍíÀÂ룩µÄ×ܶ¯ÄÜ£®·Ö±ðΪ¡÷E_k1=$\frac{1}{2}$£¨M+m£©${£¨\frac{l}{{¡÷t}_{1}}£©}^{2}$¡÷E_k2=$\frac{1}{2}$£¨M+m£©${£¨\frac{l}{{¡÷t}_{2}}£©}^{2}$£®
£¨2£©ÔÚ»¬¿é´Ó¹âµçÃÅ1Ô˶¯µ½¹âµçÃÅ2ʱ¹ý³ÌÖУ¬ÏµÍ³ÊÆÄܵļõÉÙÁ¿¡÷E_p=mgs£¨ÖØÁ¦¼ÓËÙ¶ÈΪg£©£®
£¨3£©Èç¹ûÂú×ã¹Øϵʽ£©¡÷E_p=E_k2-E_k1£¨Óá÷E_k1£¬¡÷E_k2ºÍ¡÷E_p±íʾ£©Ôò¿ÉÈÏΪÑéÖ¤ÁË»úеÄÜÊغ㶨ÂÉ£®

Answer 1

·ÖÎö ¹âµçÃŲâÁ¿Ë²Ê±ËÙ¶ÈÊÇʵÑéÖг£Óõķ½·¨£®
ÓÉÓÚ¹âµçÃŵĿí¶ÈdºÜС£¬ËùÒÔÎÒÃÇÓúܶÌʱ¼äÄÚµÄƽ¾ùËٶȴúÌæ˲ʱËٶȣ®
¸ù¾Ý¹¦ÄܹØϵµÃÖØÁ¦×ö¹¦µÄÊýÖµµÈÓÚÖØÁ¦ÊÆÄܼõСÁ¿£®
ҪעÒâ±¾ÌâµÄÑо¿¶ÔÏóÊÇϵͳ£®

½â´ð ½â£º£¨1£©ÓÉÓÚ¹âµçÃŵĿí¶ÈdºÜС£¬ËùÒÔÎÒÃÇÓúܶÌʱ¼äÄÚµÄƽ¾ùËٶȴúÌæ˲ʱËٶȣ®
»¬¿éͨ¹ý¹âµçÃÅ1ËÙ¶Èv₁=$\frac{l}{{¡÷t}_{1}}$
»¬¿éͨ¹ý¹âµçÃÅ2ËÙ¶Èv₂=$\frac{l}{{¡÷t}_{2}}$
ϵͳµÄ×ܶ¯ÄÜ·Ö±ðΪE_k1=$\frac{1}{2}$£¨M+m£©${£¨\frac{l}{{¡÷t}_{1}}£©}^{2}$ºÍE_k2=$\frac{1}{2}$£¨M+m£©${£¨\frac{l}{{¡÷t}_{2}}£©}^{2}$
£¨2£©ÔÚ»¬¿é´Ó¹âµçÃÅ1Ô˶¯µ½¹âµçÃÅ2µÄ¹ý³ÌÖУ¬ÏµÍ³ÊÆÄܵļõÉÙ¡÷E_p=mgs
£¨3£©Èç¹ûÂú×ã¹Øϵʽ¡÷E_p=E_k2-E_k1£¬¼´ÏµÍ³ÖØÁ¦ÊÆÄܼõСÁ¿µÈÓÚ¶¯ÄÜÔö¼ÓÁ¿£¬Ôò¿ÉÈÏΪÑéÖ¤ÁË»úеÄÜÊغ㶨ÂÉ£®
¹Ê´ð°¸Îª£º£¨1£©$\frac{1}{2}$£¨M+m£©${£¨\frac{l}{{¡÷t}_{1}}£©}^{2}$£¬$\frac{1}{2}$£¨M+m£©${£¨\frac{l}{{¡÷t}_{2}}£©}^{2}$
£¨2£©mgs  
£¨3£©¡÷E_p=E_k2-E_k1

µãÆÀ Á˽â¹âµçÃŲâÁ¿Ë²Ê±ËٶȵÄÔ­Àí£®
ʵÑéÖÐÎÒÃÇÒªÇå³þÑо¿¶ÔÏóºÍÑо¿¹ý³Ì£¬¶ÔÓÚϵͳÎÒÃÇÒª¿¼ÂÇÈ«Ã森