ÌâÄ¿ÄÚÈÝ
![](http://thumb.1010pic.com/pic3/upload/images/201307/34/d2681b1b.png)
3 |
2gh |
2gh |
mg
mg
£®·ÖÎö£º¶ÔСÇò½øÐÐÊÜÁ¦·ÖÎöÇó³öСÇòµÄ¼ÓËٶȣ¬ÔÙ¸ù¾ÝÔȼÓËÙÖ±ÏßÔ˶¯Î»ÒÆËٶȹ«Ê½¼´¿ÉÇó½âСÇòÔ˶¯µ½BC¸ËµÄÖеãʱµÄËٶȣ¬ÒÔCΪתÖᣬ¸ù¾ÝÁ¦¾ØƽºâÁз½³ÌÇó½â´ËʱAB¸Ë¶ÔB´¦½ÂÁ´µÄ×÷ÓÃÁ¦´óС£®
½â´ð£º½â£º¶ÔСÇò½øÐÐÊÜÁ¦·ÖÎö£¬ÈçͼËùʾ£º
¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨Âɵãº
ma=Fcos30¡ã-mgsin30¡ã=mg
ËùÒÔa=g
Ôòµ±Ð¡ÇòÔ˶¯µ½BC¸ËµÄÖеãʱ£¬Ô˶¯µÄλÒÆΪ£º
?
=h
¸ù¾ÝÔȼÓËÙÖ±ÏßÔ˶¯Î»ÒÆËٶȹ«Ê½µÃ£ºv=
=
µ±Ð¡ÇòÔ˶¯µ½BC¸ËµÄÖеãʱ£¬Ð¡Çò¶Ô¸Ë×ÓµÄ×÷ÓÃÁ¦·½Ïò´¹Ö±ÓÚ¸Ë×ÓÏòÏ£¬¸ù¾Ý¼¸ºÎ¹ØϵµÃ´óС£ºN=mgcos30¡ã=
mg
´ËʱBC¸ËÏ൱ÓÚÈÆCµãת¶¯µÄ¸Ü¸Ë£¬¸ù¾Ý¸Ü¸ËƽºâÔÀíµÃ£º
FABlBC=N?
lBC+F?
lAB
½âµÃ£ºFAB=mg
¹Ê´ð°¸Îª£º
£¬mg
![](http://thumb.1010pic.com/pic3/upload/images/201303/11/012d0a65.png)
ma=Fcos30¡ã-mgsin30¡ã=mg
ËùÒÔa=g
Ôòµ±Ð¡ÇòÔ˶¯µ½BC¸ËµÄÖеãʱ£¬Ô˶¯µÄλÒÆΪ£º
h |
sin30¡ã |
1 |
2 |
¸ù¾ÝÔȼÓËÙÖ±ÏßÔ˶¯Î»ÒÆËٶȹ«Ê½µÃ£ºv=
2ax |
2gh |
µ±Ð¡ÇòÔ˶¯µ½BC¸ËµÄÖеãʱ£¬Ð¡Çò¶Ô¸Ë×ÓµÄ×÷ÓÃÁ¦·½Ïò´¹Ö±ÓÚ¸Ë×ÓÏòÏ£¬¸ù¾Ý¼¸ºÎ¹ØϵµÃ´óС£ºN=mgcos30¡ã=
| ||
2 |
´ËʱBC¸ËÏ൱ÓÚÈÆCµãת¶¯µÄ¸Ü¸Ë£¬¸ù¾Ý¸Ü¸ËƽºâÔÀíµÃ£º
FABlBC=N?
1 |
2 |
1 |
2 |
½âµÃ£ºFAB=mg
¹Ê´ð°¸Îª£º
2gh |
µãÆÀ£º±¾ÌâÖ÷Òª¿¼²éÁËÅ£¶ÙµÚ¶þ¶¨Âɼ°¸Ü¸ËÔÀíµÄÓ¦Ó㬹ؼüÊÇÊÜÁ¦·ÖÎö£¬ÄѶÈÊÊÖУ®
![](http://thumb2018.1010pic.com/images/loading.gif)
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿