ÌâÄ¿ÄÚÈÝ
ËÉ»¨½·Àºé¼ÍÄîËþ¶Î½Ë®ÓÉÎ÷Ïò¶«Á÷£¬½¿íΪd£¬½Ë®Öи÷µãË®Á÷ËٶȴóСÓë¸÷µãµ½½Ï½ü½°¶±ßµÄ¾àÀë³ÉÕý±È£¬vË®=kx£¬k=4v0/d£¬xÊǸ÷µãµ½½ü°¶µÄ¾àÀ룮С´¬´¬Í·´¹Ö±½°¶ÓÉÄÏÏò±±¶É½£¬Ð¡´¬»®Ë®ËٶȴóС²»±äΪv0£¬ÔòÏÂÁÐ˵·¨ÖÐÕýÈ·µÄÊÇ£¨¡¡¡¡£©
·ÖÎö£º½«Ð¡´¬µÄÔ˶¯·Ö½âΪ´¹Ö±ÓÚºÓ°¶·½ÏòºÍÑغӰ¶·½Ïò£¬ÔÚ´¹Ö±ÓÚºÓ°¶·½ÏòÉÏ£¬ËٶȲ»±ä£¬Î»ÒÆËæʱ¼ä¾ùÔÈÔö´ó£¬ÔòË®Á÷ËÙ¶ÈËæʱ¼äÏȾùÔÈÔö´óºó¾ùÔȼõС£¬´Ó¶øÈ·¶¨Ô˶¯µÄ¹ì¼££»¸ù¾ÝÔ˶¯µÄºÏ³É£¬¿ÉÇó³öС´¬¶ÉºÓµÄËٶȣ®
½â´ð£º½â£ºA¡¢Ð¡´¬ÔÚÑغӰ¶·½ÏòµÄËÙ¶ÈËæʱ¼äÏȾùÔÈÔö´óºó¾ùÔȼõС£¬Òò´ËË®Á÷·½Ïò´æÔÚ¼ÓËٶȣ¬Æä·½ÏòÏÈÑØ×ÅË®Á÷·½Ïò£¬ºóÄæ×ÅË®Á÷·½Ïò£¬ÔòС´¬¶ÉºÓʱµÄ¹ì¼£ÎªÇúÏߣ®¹ÊAÕýÈ·£»C´íÎó£»
B¡¢Ð¡´¬µ½´ïÀëºÓ°¶
£¬´¦£¬Ë®Á÷ËÙΪvË®=kd=2v0£¬Ôòv=
=
v0£¬¹ÊBÕýÈ·£»
D¡¢Ð¡´¬µ½´ïÀëºÓ°¶
´¦£¬Ë®Á÷ËÙΪvË®=kd=
?
=v0£¬Ôò´¬µÄËÙ¶Èv=
v0£®¹ÊD´íÎó£®
¹ÊÑ¡AB£®
B¡¢Ð¡´¬µ½´ïÀëºÓ°¶
d |
2 |
v02+(2v0)2 |
5 |
D¡¢Ð¡´¬µ½´ïÀëºÓ°¶
3d |
4 |
4v0 |
d |
d |
4 |
2 |
¹ÊÑ¡AB£®
µãÆÀ£º½â¾ö±¾ÌâµÄ¹Ø¼üÖªµÀÔÚ´¹Ö±ÓÚºÓ°¶·½ÏòÉÏ×öÔÈËÙÖ±ÏßÔ˶¯£¬Î»ÒÆËæʱ¼ä¾ùÔÈÔö´ó£¬¸ù¾ÝºÓË®Öи÷µãË®Á÷ËÙ´óСÓë¸÷µãµ½½Ï½üºÓ°¶±ßµÄ¾àÀë³ÉÕý±È£¬ÔòË®Á÷ËÙ¶ÈËæʱ¼äÏȾùÔÈÔö´óºó¾ùÔȼõС£¬´Ó¶ø¸ù¾ÝÔ˶¯µÄºÏ³ÉÈ·¶¨Ô˶¯¹ì¼££®×¢Òâ±¾ÌâµÄXµÄº¬Ò壮
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿