ÌâÄ¿ÄÚÈÝ
¼×·½ÊÇһũ³¡£¬ÒÒ·½ÊÇÒ»¹¤³§.ÓÉÓÚÒÒ·½Éú²úÐèÕ¼Óü׷½µÄ×ÊÔ´£¬Òò´Ë¼×·½ÓÐȨÏòÒÒ·½Ë÷ÅâÒÔÃÖ²¹¾¼ÃËðʧ²¢»ñµÃÒ»¶¨¾»ÊÕÈë.ÔÚÒÒ·½²»Å⸶¼×·½µÄÇé¿öÏ£¬ÒÒ·½µÄÄêÀûÈóx£¨Ôª£©ÓëÄê²úÁ¿t£¨¶Ö£©Âú×㺯Êý¹ØÏµx=2 000
.ÈôÒÒ·½Ã¿Éú²úÒ»¶Ö²úÆ·±ØÐëÅâ
¸¶¼×·½sÔª£¨ÒÔϳÆsΪÅ⸶¼Û¸ñ£©£¬
£¨1£©½«ÒÒ·½µÄÄêÀûÈów£¨Ôª£©±íʾΪÄê²úÁ¿t£¨¶Ö£©µÄº¯Êý£¬²¢Çó³öÒÒ·½»ñµÃ×î´óÀûÈóµÄÄê²úÁ¿£»
£¨2£©¼×·½Ã¿ÄêÊÜÒÒ·½Éú²úÓ°ÏìµÄ¾¼ÃËðʧ½ð¶îy=0.002t2£¨Ôª£©£¬ÔÚÒÒ·½°´ÕÕ»ñµÃ×î´óÀûÈóµÄ²úÁ¿½øÐÐÉú²úµÄǰÌáÏ£¬¼×·½ÒªÔÚË÷ÅâÖлñµÃ×î´ó¾»ÊÕÈ룬ӦÏòÒÒ·½ÒªÇóµÄÅ⸶¼Û¸ñsÊǶàÉÙ£¿
½â£º£¨1£©ÓÉÌâÒ⣬µÃw=
-st=-s£¨
£©2+
£¨t£¾0£©.
¡àµ±
£¬¼´
¶Öʱ£¬wÈ¡µÃ×î´óֵΪ
Ôª.
¡àÒÒ·½»ñµÃ×î´óÀûÈóµÄÄê²úÁ¿Îª
¶Ö.
£¨2£©ÉèÒÒ·½°´ÕÕ»ñµÃ×î´óÀûÈóµÄ²úÁ¿½øÐÐÉú²úµÄǰÌáÏ£¬¼×·½ÔÚË÷ÅâÖлñµÃµÄ¾»ÊÕÈëΪVÔª£¬Ôòt=
¶Ö£¬V=st-0.002t2=
-
£¬
V¡ä=
+
=
.
ÁîV¡ä=0£¬µÃs=20.µ±s£¾20ʱ£¬V¡ä£¼0£¬ËùÒÔVÔÚ£¨20£¬+¡Þ£©Éϵ¥µ÷µÝ¼õ£»µ±s£¼20ʱ£¬V¡ä£¾0£¬ËùÒÔVÔÚ£¨0£¬20£©Éϵ¥µ÷µÝÔö.ËùÒÔs=20ʱ£¬VÈ¡µÃ¼«´óÖµ£¬Ò²¾ÍÊÇ×î´óÖµ.ËùÒÔÔÚÒÒ·½°´ÕÕ»ñµÃ×î´óÀûÈóµÄ²úÁ¿½øÐÐÉú²úµÄǰÌáÏ£¬¼×·½ÒªÔÚË÷ÅâÖлñµÃ×î´ó¾»ÊÕÈ룬ӦÏòÒÒ·½ÒªÇóµÄÅ⸶¼Û¸ñsÊÇ20Ôª.
µãÆÀ£º±¾ÌâÖ÷Òª¿¼²éº¯Êý×îÖµµÄÇ󷨼°µ¼ÊýÔÚº¯Êý×îÖµÇó½âÖеÄÓ¦ÓÃÒÔ¼°ÔËÓÃÊýѧ֪ʶ½â¾öʵ¼ÊÎÊÌâµÄÄÜÁ¦£¬Í¬Ê±¿¼²éÔĶÁÀí½âÄÜÁ¦.