¡¾´ð°¸¡¿
·ÖÎö£ºÒÔmΪÑо¿¶ÔÏó½øÐзÖÎö£¬mÔÚ³µ°åÉϵÄˮƽ·½ÏòÖ»ÊÜÒ»¸öĦ²ÁÁ¦fµÄ×÷Óã¬ËùÒÔm´ÓAµãÔ˶¯µ½Bµã£¬×öÔȼÓËÙÖ±ÏßÔ˶¯£¬¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨Âɼ°Ô˶¯Ñ§»ù±¾¹«Ê½Çó³öÔ˶¯µ½BµãµÄËٶȡ¢Î»ÒƵȣ¬ÒÔС³µÎªÑо¿¶ÔÏó£¬Çó³öƽ°å³µµÄËٶȣ»m´ÓB´¦»¬Âäʱ£¬ÒÔ¦Ô
BΪ³õËÙ¶È×öƽÅ×Ô˶¯£¬¸ù¾ÝƽÅ×Ô˶¯µÄ»ù±¾¹«Ê½Çó³öÔ˶¯µÄʱ¼äºÍλÒÆ£¬¶Ôƽ°å³µM£¬ÔÚm们Âä֮ǰ£¬Ë®Æ½·½ÏòÊܶþÁ¦×÷Ó㬼´FºÍÎï¿é¶Ôƽ°å³µµÄĦ²ÁÁ¦f£¬¶þÕß·½ÏòÏà·´£¬µ±m´Óƽ°å³µµÄBµã»¬ÂäÒÔºó£¬Æ½°å³µË®Æ½·½ÏòÖ»ÊÜF×÷Óã¬×öÔȼÓËÙÖ±ÏßÔ˶¯£¬·Ö±ð¸ù¾ÝÔ˶¯Ñ§»ù±¾¹«Ê½Çó³öλÒÆ£¬½ø¶ø¿ÉÇóµÃÎï¿éÂäµØʱ£¬ÂäµØµãµ½³µÎ²µÄˮƽ¾àÀës
½â´ð£º½â£º£¨1£©ÒÔmΪÑо¿¶ÔÏó½øÐзÖÎö£¬mÔÚˮƽ·½ÏòÖ»ÊÜÒ»¸öĦ²ÁÁ¦fµÄ×÷Óã¬f=¦Ìmg£¬
¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉÖªf=ma
1 a
1=¦Ìg=0.20×10m/s
2=2m/s
2 Èçͼ£¬
m´ÓAµãÔ˶¯µ½Bµã£¬×öÔȼÓËÙÖ±ÏßÔ˶¯£¬s
AB=s
-b=1.00m£¬
Ô˶¯µ½BµãµÄËٶȦÔ
BΪ£º¦Ô
B=
m/s=2m/s
Îï¿éÔÚƽ°å³µÉÏÔ˶¯Ê±¼äΪt
1=
=
s=1s£¬ÔÚÏàͬʱ¼äÀïƽ°å³µÏòÇ°ÐÐÊ»µÄ¾àÀës
=3.0m£¬Ôò£ºs
=
a
2t
12£¬
ËùÒÔƽ°å³µµÄ¼ÓËٶȣºa
2=
=
=6m/s
2 ´Ëʱƽ°å³µµÄËÙ¶ÈΪ£ºv
2=a
2t
1=6×1=6m/s
£¨2£©m´ÓB´¦»¬Âäʱ£¬ÒÔ¦Ô
BΪ³õËÙ¶È×öƽÅ×Ô˶¯£¬Âäµ½CµÄˮƽ¾àÀëΪs
1£¬ÏÂÂäʱ¼äΪt
2£¬
Ôò h=
gt
22 t
2=
=0.5s
s
1=v
Bt
2=2×0.5m=1.0 m
¶Ôƽ°å³µM£¬ÔÚm们Âä֮ǰ£¬Ë®Æ½·½ÏòÊܶþÁ¦×÷Ó㬼´FºÍÎï¿é¶Ôƽ°å³µµÄĦ²ÁÁ¦f£¬¶þÕß·½ÏòÏà·´£¬Æ½°å³µ¼ÓËÙ¶ÈΪa
2£¬ÓÉÅ£¶ÙµÚ¶þ¶¨ÂɵãºF-f=Ma
2ÔòÓУºF=Ma
2+f=£¨100×4+0.2×50×10£©N=500N
µ±m´Óƽ°å³µµÄBµã»¬ÂäÒÔºó£¬Æ½°å³µË®Æ½·½ÏòÖ»ÊÜF×÷Ó㬶ø×ö¼ÓËÙ¶ÈΪa
3µÄÔȼÓËÙÔ˶¯£¬
ÓÉÅ£¶ÙµÚ¶þ¶¨ÂɵãºF=Ma
3 ¼´a3=
=5m/s
2ÔÚm´ÓB»¬Âäµ½CµãµÄʱ¼ät=0.5sÄÚ£¬MÔ˶¯¾àÀës
2Ϊ£ºs
2=v
2t+
a
3t
2=3.625m
Îï¿éÂäµØʱ£¬ÂäµØµãµ½³µÎ²µÄˮƽ¾àÀësΪ£º
s=s
2-s
1=£¨3.625-1£©m=2.625m
´ð£ºÎï¿éÂäµØʱ£¬ÂäµØµãµ½³µÎ²µÄˮƽ¾àÀësΪ2.625m£®
µãÆÀ£º¸ÃÌâÉæ¼°µ½Ïà¶ÔÔ˶¯µÄ¹ý³Ì£¬ÒªÇóͬѧÃÇÄܸù¾ÝÊÜÁ¦Çé¿öÕýÈ··ÖÎöÔ˶¯Çé¿ö£¬²¢ÄÜÊìÁ·ÔËÓÃÔ˶¯Ñ§»ù±¾¹«Ê½½âÌ⣬ÄѶȽϴó£®