ÌâÄ¿ÄÚÈÝ

£¨1£©ÎïÌåÔ˶¯ÖÁAµãµÄËٶȴóС£»
£¨2£©ÎïÌåÔ˶¯µ½Ô²»¡¹ìµÀ×îµÍµãOʱ¶Ô¹ìµÀµÄѹÁ¦£®
·ÖÎö£º£¨1£©¸ù¾Ý¸ß¶ÈÇó³öƽÅ×Ô˶¯µÄʱ¼ä£¬´Ó¶øÇó³öAµãÊúÖ±·½ÏòÉϵķÖËٶȣ¬¸ù¾ÝƽÐÐËıßÐζ¨ÔòÇó³öÎïÌåÔ˶¯µ½AµãµÄËٶȣ®
£¨2£©¸ù¾Ý¶¯Äܶ¨ÀíÇó³öÎïÌåÔ˶¯µ½×îµÍµãʱµÄËٶȣ¬¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉÇó³öÖ§³ÖÁ¦µÄ´óС£¬´Ó¶øµÃ³öÎïÌå¶Ô¹ìµÀѹÁ¦µÄ´óС£®
£¨2£©¸ù¾Ý¶¯Äܶ¨ÀíÇó³öÎïÌåÔ˶¯µ½×îµÍµãʱµÄËٶȣ¬¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉÇó³öÖ§³ÖÁ¦µÄ´óС£¬´Ó¶øµÃ³öÎïÌå¶Ô¹ìµÀѹÁ¦µÄ´óС£®
½â´ð£º½â£º£¨1£©ÓÉh=
gt2£¬µÃƽÅ×ËùÓõÄʱ¼äΪt=
=
s=0.4s£®
µ½´ïAµãʱÊúÖ±·½ÏòµÄËÙ¶ÈΪvy=gt=4m/s£®
ƽÅ׵ijõËÙ¶ÈΪ£ºv0=vycot53¡ã=4¡Á0.75m/s=3m/s£®
µ½´ïAµãµÄËٶȴóСΪ£ºv=
=5m/s£®
£¨2£©ÉèÎïÌåÔ˶¯µ½Ô²»¡×îµÍµãʱµÄËÙ¶ÈΪv¡ä£¬ÓÉ»úеÄÜÊغ㶨ÂÉÓУº
mv¡ä2-
mv2=mgR(1-cos53¡ã)
ÓÖÓÉÅ£¶ÙµÚ¶þ¶¨ÂÉÓУºFÖ§-mg=m
´úÈëÊý¾Ý£¬ÁªÁ¢½âµÃ£ºFÖ§=43N
ÓÉÅ£¶ÙµÚÈý¶¨ÂÉ£¬Ð¡Çò¶Ô¹ìµÀµÄѹÁ¦´óСΪ43N£®
´ð£º£¨1£©ÎïÌåÔ˶¯ÖÁAµãµÄËٶȴóСΪ5m/s£»
£¨2£©ÎïÌåÔ˶¯µ½Ô²»¡¹ìµÀ×îµÍµãOʱ¶Ô¹ìµÀµÄѹÁ¦Îª43N£®
1 |
2 |
|
|
µ½´ïAµãʱÊúÖ±·½ÏòµÄËÙ¶ÈΪvy=gt=4m/s£®
ƽÅ׵ijõËÙ¶ÈΪ£ºv0=vycot53¡ã=4¡Á0.75m/s=3m/s£®
µ½´ïAµãµÄËٶȴóСΪ£ºv=
v02+vy2 |
£¨2£©ÉèÎïÌåÔ˶¯µ½Ô²»¡×îµÍµãʱµÄËÙ¶ÈΪv¡ä£¬ÓÉ»úеÄÜÊغ㶨ÂÉÓУº
1 |
2 |
1 |
2 |
ÓÖÓÉÅ£¶ÙµÚ¶þ¶¨ÂÉÓУºFÖ§-mg=m
v¡ä2 |
R |
´úÈëÊý¾Ý£¬ÁªÁ¢½âµÃ£ºFÖ§=43N
ÓÉÅ£¶ÙµÚÈý¶¨ÂÉ£¬Ð¡Çò¶Ô¹ìµÀµÄѹÁ¦´óСΪ43N£®
´ð£º£¨1£©ÎïÌåÔ˶¯ÖÁAµãµÄËٶȴóСΪ5m/s£»
£¨2£©ÎïÌåÔ˶¯µ½Ô²»¡¹ìµÀ×îµÍµãOʱ¶Ô¹ìµÀµÄѹÁ¦Îª43N£®
µãÆÀ£ºÆ½Å×Ô˶¯ÔÚˮƽ·½ÏòÉÏ×öÔÈËÙÖ±ÏßÔ˶¯£¬ÔÚÊúÖ±·½ÏòÉÏ×ö×ÔÓÉÂäÌåÔ˶¯£¬ÖªµÀƽÅ×Ô˶¯Ë®Æ½·½ÏòºÍÊúÖ±·½ÏòÉϵÄÔ˶¯¹æÂÉ£¬ÒÔ¼°Ô²ÖÜÔ˶¯ÏòÐÄÁ¦µÄÀ´Ô´Êǽâ¾ö±¾ÌâµÄ¹Ø¼ü£®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿