ÌâÄ¿ÄÚÈÝ
ΪÁ˼õÉÙÕ½¶·»úÆð·ÉʱÔÚ¼×°åÉϼÓËÙµÄʱ¼äºÍ¾àÀ룬ÏÖ´úº½Ä¸´ó¶à²ÉÓÃÁËÕôÆûµ¯Éä¼¼Êõ¡£Ò»¼Ü×ÜÖÊÁ¿M=5.0¡Á103kgµÄÕ½»úÈç¹û²ÉÓû¬ÐмÓËÙ£¨Ö»ÒÀ¿¿×ÔÉí¶¯Á¦ÏµÍ³¼ÓËÙ£©£¬Òª´ïµ½vo=60m£¯sµÄÆð·ÉËÙ¶È£¬¼×°åˮƽÅܵÀµÄ³¤¶ÈÖÁÉÙΪ120m¡£²ÉÓÃÕôÆûµ¯Éä¼¼Êõ£¬Õ½»úÔÚ×ÔÉí¶¯Á¦ºÍ³ÖÐøµÄÕôÆû¶¯Á¦¹²Í¬×÷ÓÃÏÂֻҪˮƽ¼ÓËÙ60m¾ÍÄÜ´ïµ½Æð·ÉËÙ¶È¡£¼ÙÉèÕ½»úÆð·É¹ý³ÌÊÇÔȼÓËÙÖ±ÏßÔ˶¯£¬º½Ä¸±£³Ö¾²Ö¹£¬¿ÕÆø×èÁ¦´óС²»±ä£¬È¡g=l0m£¯s2¡£
£¨1£©²ÉÓÃÕôÆûµ¯Éä¼¼Êõ£¬ÇóÕ½»ú¼ÓËÙ¹ý³ÌÖмÓËÙ¶È´óСÒÔ¼°ÖÊÁ¿m=60kgµÄ·ÉÐÐÔ±Êܵ½×ùÒÎ×÷ÓÃÁ¦µÄ´óС£»
£¨2£©²ÉÓÃÕôÆûµ¯Éä¼¼Êõ£¬µ¯ÉäϵͳµÄµ¯Á¦Îª¶à´ó£¿µ¯Á¦ÔÚ¼ÓËÙ60mµÄ¹ý³ÌÖжÔÕ½»ú×öµÄ¹¦ÊǶàÉÙ£¿
£¨1£©²ÉÓÃÕôÆûµ¯Éä¼¼Êõ£¬ÇóÕ½»ú¼ÓËÙ¹ý³ÌÖмÓËÙ¶È´óСÒÔ¼°ÖÊÁ¿m=60kgµÄ·ÉÐÐÔ±Êܵ½×ùÒÎ×÷ÓÃÁ¦µÄ´óС£»
£¨2£©²ÉÓÃÕôÆûµ¯Éä¼¼Êõ£¬µ¯ÉäϵͳµÄµ¯Á¦Îª¶à´ó£¿µ¯Á¦ÔÚ¼ÓËÙ60mµÄ¹ý³ÌÖжÔÕ½»ú×öµÄ¹¦ÊǶàÉÙ£¿
½â£º£¨1£©ÉèÕ½»úÔÚ×ÔÉí¶¯Á¦ºÍÕôÆû¶¯Á¦¹²Í¬×÷ÓÃÏ»¬ÐеļÓËÙ¶ÈΪa£¬Ôò
v02=2as
½âµÃa=30m/s2
·ÉÐÐÔ±Êܵ½×ùÒÎˮƽ·½ÏòµÄ×÷ÓÃÁ¦Fx=ma=1.8¡Á103N
·ÉÐÐÔ±Êܵ½×ùÒÎÊúÖ±·½ÏòµÄ×÷ÓÃÁ¦Fy=mg=6.0¡Á102N
·ÉÐÐÔ±Êܵ½×ùÒÎ×÷ÓÃÁ¦µÄ´óС
£¨2£©ÉèÕ½»úÖ»ÒÀ¿¿×ÔÉí¶¯Á¦×÷ÓÃÏ»¬ÐеļÓËÙ¶ÈΪa1£¬¿ÕÆø×èÁ¦Îªf£¬×ÔÉí¶¯Á¦´óСF1£¬µ¯ÉäϵͳµÄµ¯Á¦´óСF2£¬Ôò
v02=2a1s1
F1£f=Ma1
F2£«F1£f=Ma
´úÈëÊý¾ÝµÃF2=7.5¡Á104N
µ¯ÉäϵͳµÄµ¯Á¦¶ÔÕ½»ú×öµÄ¹¦W2=F2s=4.5¡Á106J
v02=2as
½âµÃa=30m/s2
·ÉÐÐÔ±Êܵ½×ùÒÎˮƽ·½ÏòµÄ×÷ÓÃÁ¦Fx=ma=1.8¡Á103N
·ÉÐÐÔ±Êܵ½×ùÒÎÊúÖ±·½ÏòµÄ×÷ÓÃÁ¦Fy=mg=6.0¡Á102N
·ÉÐÐÔ±Êܵ½×ùÒÎ×÷ÓÃÁ¦µÄ´óС
£¨2£©ÉèÕ½»úÖ»ÒÀ¿¿×ÔÉí¶¯Á¦×÷ÓÃÏ»¬ÐеļÓËÙ¶ÈΪa1£¬¿ÕÆø×èÁ¦Îªf£¬×ÔÉí¶¯Á¦´óСF1£¬µ¯ÉäϵͳµÄµ¯Á¦´óСF2£¬Ôò
v02=2a1s1
F1£f=Ma1
F2£«F1£f=Ma
´úÈëÊý¾ÝµÃF2=7.5¡Á104N
µ¯ÉäϵͳµÄµ¯Á¦¶ÔÕ½»ú×öµÄ¹¦W2=F2s=4.5¡Á106J
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿