ÌâÄ¿ÄÚÈÝ
£¨2008?ÐÂÒÊÊÐÄ£Ä⣩ijһ·¢´ï¹ú¼ÒµÄÓԱÍê³ÉÁ˶ԻðÐDZíÃæµÄ¿Æѧ¿¼²ìÈÎÎñ£¬³Ë×ø·µ»Ø²Õ·µ»ØΧÈÆ»ðÐÇ×öÔ²ÖÜÔ˶¯µÄ¹ìµÀ²Õ£¬ÈçͼËùʾ£®ÎªÁË°²È«£¬·µ»Ø²ÕÓë¹ìµÀ²Õ¶Ô½Óʱ£¬±ØÐë¾ßÓÐÏàͬµÄËٶȣ®ÒÑÖª·µ»Ø²Õ·µ»Ø¹ý³ÌÖÐÐè¿Ë·þ»ðÐǵÄÒýÁ¦¶ø×öµÄ¹¦¿ÉÓÉÈçϹ«Ê½¼ÆË㣺W=mgR(1-
)£¬ÆäÖУºRΪ»ðÐǵİ뾶£¬rΪ¹ìµÀ²Õµ½»ðÐÇÖÐÐĵľàÀ룬mΪ·µ»Ø²ÕÓëÈ˵Ä×ÜÖÊÁ¿£¬gΪ»ðÐDZíÃæµÄÖØÁ¦¼ÓËٶȣ®ÒÑÖª±¾´Î¿Æѧ¿¼²ìÖйìµÀ²Õµ½»ðÐÇÖÐÐĵľàÀër=
R£¬Éè m¡¢R¡¢gΪÒÑÖªµÄÎïÀíÁ¿£®²»¼Æ»ðÐDZíÃæ´óÆø¶Ô·µ»Ø²ÕµÄ×èÁ¦ºÍ»ðÐÇ×ÔתµÄÓ°Ï죬Ôò¸ÃÓԱ³Ë×øµÄ·µ»Ø²ÕÖÁÉÙÐèÒª»ñµÃ¶àÉÙÄÜÁ¿²ÅÄÜÍê³ÉÓë¹ìµÀ²Õ¶Ô½Ó£¿°²È«·µ»Øµ½¹ìµÀ²Õ£®
R |
r |
4 |
3 |
·ÖÎö£º¸ù¾Ý»ðÐDZíÃæµÄÖØÁ¦µÈÓÚÍòÓÐÒýÁ¦ÁгöµÈʽ£®
Ñо¿¹ìµÀ²ÕÈÆÎÀÐÇ×öÔÈËÙÔ²ÖÜÔ˶¯£¬¸ù¾ÝÍòÓÐÒýÁ¦ÌṩÏòÐÄÁ¦£¬ÁгöµÈʽÇó½âÓԱ³Ë×ø·µ»Ø²ÕÓë¹ìµÀ²Õ¶Ô½ÓʱËٶȣ®
¸ù¾ÝÄÜÁ¿ÊغãÇó½â·µ»Ø¹ìµÀ²ÕÖÁÉÙÐèÒª»ñµÃµÄÄÜÁ¿£®
Ñо¿¹ìµÀ²ÕÈÆÎÀÐÇ×öÔÈËÙÔ²ÖÜÔ˶¯£¬¸ù¾ÝÍòÓÐÒýÁ¦ÌṩÏòÐÄÁ¦£¬ÁгöµÈʽÇó½âÓԱ³Ë×ø·µ»Ø²ÕÓë¹ìµÀ²Õ¶Ô½ÓʱËٶȣ®
¸ù¾ÝÄÜÁ¿ÊغãÇó½â·µ»Ø¹ìµÀ²ÕÖÁÉÙÐèÒª»ñµÃµÄÄÜÁ¿£®
½â´ð£º½â£º·µ»Ø²ÕÓëÈËÔÚ»ðÐDZíÃ渽½üÓУºG
=mg
Éè·µ»Ø²ÕÓë¹ìµÀ²Õ¶Ô½ÓʱËٶȴóСΪv£¬Ôò£ºG
=m
·µ»Ø²ÕÓë¹ìµÀ²Õ¶Ô½Óʱ£¬¾ßÓеĶ¯ÄÜΪ£ºEK=
mv2
°ÑÉÏÃæÁ½Ê½´úÈ룬µÃ£ºEK=
mgR
·µ»Ø²Õ·µ»Ø¹ý³Ì¿Ë·þÒýÁ¦×ö¹¦W=mgR(1-
)=
mgR
ËùÒÔ·µ»Ø²Õ·µ»ØʱÖÁÉÙÐèÒªÄÜÁ¿E=EK+W=
mgR
´ð£º¸ÃÓԱ³Ë×øµÄ·µ»Ø²ÕÖÁÉÙÐèÒª»ñµÃ
mgRÄÜÁ¿²ÅÄÜÍê³ÉÓë¹ìµÀ²Õ¶Ô½Ó°²È«·µ»Øµ½¹ìµÀ²Õ£®
Mm |
R2 |
Éè·µ»Ø²ÕÓë¹ìµÀ²Õ¶Ô½ÓʱËٶȴóСΪv£¬Ôò£ºG
Mm |
r2 |
v2 |
r |
·µ»Ø²ÕÓë¹ìµÀ²Õ¶Ô½Óʱ£¬¾ßÓеĶ¯ÄÜΪ£ºEK=
1 |
2 |
°ÑÉÏÃæÁ½Ê½´úÈ룬µÃ£ºEK=
3 |
8 |
·µ»Ø²Õ·µ»Ø¹ý³Ì¿Ë·þÒýÁ¦×ö¹¦W=mgR(1-
R |
r |
1 |
4 |
ËùÒÔ·µ»Ø²Õ·µ»ØʱÖÁÉÙÐèÒªÄÜÁ¿E=EK+W=
5 |
8 |
´ð£º¸ÃÓԱ³Ë×øµÄ·µ»Ø²ÕÖÁÉÙÐèÒª»ñµÃ
5 |
8 |
µãÆÀ£ºÏòÐÄÁ¦µÄ¹«Ê½Ñ¡È¡Òª¸ù¾ÝÌâÄ¿ÌṩµÄÒÑÖªÎïÀíÁ¿»òËùÇó½âµÄÎïÀíÁ¿Ñ¡È¡Ó¦Óã®
ºöÂÔÐÇÇò×ÔתµÄÓ°Ï죬Äܸù¾ÝÍòÓÐÒýÁ¦µÈÓÚÖØÁ¦ÁгöµÈʽ£®
ºöÂÔÐÇÇò×ÔתµÄÓ°Ï죬Äܸù¾ÝÍòÓÐÒýÁ¦µÈÓÚÖØÁ¦ÁгöµÈʽ£®
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿