Question

18£®ÔÚ¹«Â·µÄÊ®×Ö·¿Ú£¬ºìµÆÀ¹Í£Á˺ܶàÆû³µ£¬À¹Í£µÄÆû³µÅųɱÊÖ±µÄÒ»ÁУ¬×îÇ°ÃæµÄÒ»Á¾Æû³µµÄÇ°¶Ë¸ÕºÃÓë·¿ÚÍ£³µÏßÏàÆ룬ÏàÁÚÁ½³µµÄÇ°¶ËÖ®¼äµÄ¾àÀë¾ùΪL=6m£¬ÈôÆû³µÆð¶¯Ê±¶¼ÒÔa=2.5m/s²µÄ¼ÓËÙ¶È×öÔȼÓËÙÔ˶¯£¬¼ÓËÙµ½v=10m/sºó×öÔÈËÙÔ˶¯Í¨¹ý·¿Ú£® ¸Ã·¿ÚÁÁÂ̵Æʱ¼ät=40s£®ÁíÍ⽻ͨ¹æÔò¹æ¶¨£ºÔ­ÔÚÂ̵ÆʱͨÐеÄÆû³µ£¬ºìµÆÁÁÆðʱ£¬³µÍ· ÒÑÔ½¹ýÍ£³µÏßµÄÆû³µÔÊÐíͨ¹ý£®Çë½â´ðÏÂÁÐÎÊÌ⣺
£¨1£©ÈôÂ̵ÆÁÁÆð˲ʱ£¬ËùÓÐ˾»úͬʱÆð¶¯Æû³µ£¬ÎÊÓжàÉÙÁ¾Æû³µÄÜͨ¹ý·¿Ú£»
£¨2£©ÊÂʵÉÏÓÉÓÚÈË·´Ó¦Ê±¼äµÄ´æÔÚ£¬Â̵ÆÁÁÆðʱ²»¿ÉÄÜËùÓÐ˾»úͬʱÆð¶¯Æû³µ£®ÏÖ¼ÙÉèÂ̵ÆÁÁÆðʱ£¬µÚÒ»¸ö˾»ú³Ùºó¡÷t=0.90sÆð¶¯Æû³µ£¬ºóÃæ˾»ú¶¼±ÈÇ°Ò»Á¾³µ³Ùºó¡÷t=0.90sÆð¶¯Æû³µ£¬ÔÚ¸ÃÇé¿öÏ£¬ÓжàÉÙÁ¾³µÄÜͨ¹ý·¿Ú£®

Answer 1

·ÖÎö £¨1£©ÏÈÇó³ö¼ÓËÙµÄʱ¼ä£¬¸ù¾ÝÔ˶¯Ñ§»ù±¾¹«Ê½Çó³ö 40.0 sʱ¼ä£¬Æû³µÄÜÐÐÊ»µÄλÒÆ£¬´Ó¶øÇó³öÄÜͨ¹ý·¿ÚµÄÆû³µ£»
£¨2£©ÉèÄÜͨ¹ýkÁ¾Æû³µ£¬ÔòµÚkÁ¾Æû³µÄÜͨ¹ý·¿ÚÒªÂú×ã$\frac{1}{2}a{{t}_{1}}^{2}+v£¨t-{t}_{1}-k¡÷t£©¡Ý£¨k-1£©L$£¬´úÈëÊý¾Ý¼´¿ÉÇó½â£®

½â´ð ½â£º£¨1£©Æû³µ¼ÓËÙʱ¼ä${t}_{1}=\frac{v}{a}=\frac{10}{2.5}s=4s$£¬
40sʱ¼äÄÚ£¬Æû³µÐÐÊ»µÄ¾àÀë$x=\frac{1}{2}a{{t}_{1}}^{2}+v£¨t-{t}_{1}£©$=$\frac{1}{2}¡Á2.5¡Á16+10¡Á£¨40-4£©m$=380m£®
n=$\frac{x}{L}=\frac{380}{6}¡Ö63.3$£¬
¸ù¾ÝÌâÒâÖª£¬ÄÜÓÐ64Á¾³µÍ¨¹ý·¿Ú£®
£¨2£©ÉèÄÜͨ¹ýkÁ¾Æû³µ£¬ÔòµÚkÁ¾Æû³µÍ¨¹ý·¿ÚÒªÂú×㣺$\frac{1}{2}a{{t}_{1}}^{2}+v£¨t-{t}_{1}-k¡÷t£©¡Ý£¨k-1£©L$£¬
´úÈëÊý¾Ýºó½âµÃk$¡Ü\frac{386}{15}$£¬
ËùÒÔÄÜͨ¹ý25Á¾Æû³µ£®
´ð£º£¨1£©ÓÐ64Á¾Æû³µÄÜͨ¹ý·¿Ú£»
£¨2£©ÔÚ¸ÃÇé¿öÏ£¬ÓÐ25Á¾³µÄÜͨ¹ý·¿Ú£®

µãÆÀ ±¾ÌâÖ÷Òª¿¼²éÁËÔ˶¯Ñ§»ù±¾¹«Ê½µÄÖ±½ÓÓ¦Óã¬ÒªÇóͬѧÃÇÄÜÕýÈ··ÖÎöÆû³µµÄÔ˶¯Çé¿ö£¬ÄѶÈÊÊÖУ®