Question

8£®ÈçͼËùʾ£¬¾¢¶ÈϵÊýΪkµÄÇᵯ»ÉµÄÒ»¶Ë¹Ì¶¨ÔÚǽÉÏ£¬ÁíÒ»¶ËÓëÖÃÓÚˮƽÃæÉÏÖÊÁ¿ÎªmµÄÎïÌåA½Ó´¥£¬µ«Î´ÓëÎïÌåAÁ¬½Ó£¬µ¯»ÉˮƽÇÒÎÞÐα䣮ÏÖ¶ÔÎïÌåAÊ©¼ÓÒ»¸öˮƽÏòÓÒµÄ˲¼ä³åÁ¿´óСΪI£¬²âµÃÎïÌåAÏòÓÒÔ˶¯µÄ×î´ó¾àÀëΪx₀£¬Ö®ºóÎïÌåA±»µ¯»Éµ¯»Ø×îÖÕÍ£ÔÚ¾àÀë³õʼλÖÃ×ó²à2x₀´¦£®ÒÑÖªµ¯»ÉʼÖÕÔÚµ¯»Éµ¯ÐÔÏÞ¶ÈÄÚ£¬ÎïÌåAÓëˮƽÃæ¼äµÄ¶¯Ä¦²ÁÒòÊýΪ¦Ì£¬ÖØÁ¦¼ÓËÙ¶ÈΪg£¬ÏÂÁÐ˵·¨ÖÐÕýÈ·µÄÊÇ£¨¡¡¡¡£©

• A£® ÎïÌåAÕû¸öÔ˶¯¹ý³Ì£¬µ¯»É¶ÔÎïÌåAµÄ³åÁ¿ÎªÁã
• B£® ÎïÌåAÏòÓÒÔ˶¯¹ý³ÌÖÐÓ뵯»É½Ó´¥µÄʱ¼äÒ»¶¨Ð¡ÓÚÎïÌåAÏò×óÔ˶¯¹ý³ÌÖÐÓ뵯»É½Ó´¥µÄʱ¼ä
• C£® ÎïÌåAÏò×óÔ˶¯Ô˶¯¹ý³ÌÖÐ×î´ó¶¯ÄÜΪ$\frac{I^2}{2m}$-2¦Ìmgx₀
• D£® ÎïÌåAÓ뵯»É×÷ÓõĹý³ÌÖУ¬ÏµÍ³µÄ×î´óµ¯ÐÔÊÆÄÜ$\frac{I^2}{2m}-¦Ìmg{x_0}$

Answer 1

·ÖÎö ¶ÔÎïÌåµÄÔ˶¯¹ý³Ì½øÐзÖÎö£¬ÓɳåÁ¿µÄ¶¨Òå¿ÉÃ÷È·µ¯Á¦µÄ³åÁ¿£»¸ù¾ÝÔ˶¯¹ý³Ì·ÖÎöÒÔ¼°Å£¶ÙµÚ¶þ¶¨ÂÉ¿ÉÃ÷È·ÎïÌåÏò×óºÍÏòÓÒÔ˶¯¹ý³ÌÖеļÓËٶȣ¬Ôò¿ÉÃ÷È·¶ÔÓ¦µÄʱ¼ä´óС£»ÎïÌåÔÚÏò×óÔ˶¯ÖÁµ¯Á¦ÓëĦ²ÁÁ¦ÏàµÈʱËٶȴï×î´ó£¬¸ù¾Ý¹¦ÄܹØϵ¿ÉÇóµÃÎïÌåµÄ×î´ó¶¯ÄÜÒÔ¼°×î´óµ¯ÐÔÊÆÄÜ£®

½â´ð ½â£ºA¡¢ÓÉÓÚµ¯»ÉµÄµ¯Á¦Ò»Ö±Ïò×󣬹ʵ¯Á¦µÄ³åÁ¿²»¿ÉÄÜΪÁ㣻¹ÊA´íÎó£»
B¡¢ÎïÌåÏòÓÒÔ˶¯¹ý³ÌÊÜÏò×óµÄµ¯Á¦ºÍĦ²ÁÁ¦£¬¶øÏò×óÔ˶¯¹ý³ÌÖÐÊÜÏò×óµÄµ¯Á¦ÓëÏòÓÒµÄĦ²ÁÁ¦£¬Òò´ËÏò×óÔ˶¯Ê±µÄ¼ÓËÙ¶ÈСÓÚÏòÓÒÔ˶¯Ê±µÄ¼ÓËٶȣ»¶øÓ뵯»É½Ó´¥Ïò×óºÍÏòÓÒµÄλÒÆ´óСÏàµÈ£¬ÔòÓÉλÒƹ«Ê½¿ÉµÃ£¬ÏòÓÒÔ˶¯µÄʱ¼äÒ»¶¨Ð¡ÓÚÏò×óÔ˶¯µÄʱ¼ä£»¹ÊBÕýÈ·£»
C¡¢Óɶ¯Á¿¶¨Àí¿ÉÖªI₀=mv₀£»ÔòÓɹ¦ÄܹØϵ֪£¬ÏµÍ³¾ßÓеÄ×î´óµ¯ÐÔÊÆÄÜE_P=$\frac{1}{2}m{{v}_{0}}^{2}-¦Ìmg{x}_{0}$=$\frac{{I}^{2}}{2m}-¦Ìmg{x}_{0}$£¬
ÎïÌåÔÚÏò×óÔ˶¯ÖÁµ¯Á¦ÓëĦ²ÁÁ¦ÏàµÈʱËٶȴï×î´ó£¬¶¯ÄÜ×î´ó£¬ÉèÎïÌåµÄ×î´ó¶¯ÄÜΪE_km£®´ËʱµÄѹËõÁ¿Îªx£¬µ¯»ÉµÄµ¯ÐÔÊÆÄÜΪE_P£®´Ó¶¯ÄÜ×î´óλÖõ½×î×ó¶ËµÄ¹ý³Ì£¬Óɹ¦ÄܹØϵÓУºE_km+E_P=¦Ìmg•£¨x+2x₀£©
´Ó¿ªÊ¼µ½Ïò×ó¶¯ÄÜ×î´óµÄ¹ý³Ì£¬ÓУº$\frac{{I}^{2}}{2m}$=E_km+E_P+¦Ìmg•£¨2x₀-x£©£¬
ÁªÁ¢½âµÃ£ºE_km=$\frac{{I}^{2}}{2m}-2¦Ìmgx£¾\frac{{I}^{2}}{2m}-2¦Ìmg{x}_{0}$£¬¹ÊC´íÎó£¬DÕýÈ·£®
¹ÊÑ¡£ºBD£®

µãÆÀ ±¾ÌâΪÁ¦Ñ§×ÛºÏÐÔÌâÄ¿£¬ÌâÄ¿Éæ¼°¹¦ÄܹØϵ¡¢Å£¶ÙµÚ¶þ¶¨Âɼ°Ô˶¯Ñ§¹«Ê½£¬»¹Óж¯Á¿¶¨ÀíµÈÄÚÈÝ£¬ÒªÇóѧÉúÄÜÕýÈ··ÖÎöÎÊÌ⣬¸ù¾ÝÌâÒâÃ÷È·Ëù¶ÔÓ¦µÄÎïÀí¹æÂɵÄÓ¦Óã®