Question

8£®¾²Ö¹Ôڹ⻬ˮƽÃæÉÏÖÊÁ¿ÎªmµÄСÎï¿é£¬ÔÚÖ±ÏßMNµÄ×ó±ßÖ»Êܵ½Ë®Æ½Á¦F₁×÷Óã¨Ð¡Îï¿é¿ÉÊÓΪÖʵ㣩£¬ÔÚMNµÄÓұ߳ýÊÜF₁Í⻹Êܵ½ÓëF₁ÔÚͬһÌõÖ±ÏßÉϵĺãÁ¦F₂×÷Óã¬ÏÖʹСÎï¿éÓÉAµã´Ó¾²Ö¹¿ªÊ¼Ô˶¯£¬Èçͼ£¨a£©Ëùʾ£¬Ð¡Îï¿éÔ˶¯µÄv-tͼÏóÈçͼ£¨b£©Ëùʾ£¬ÏÂÁÐ˵·¨ÖÐÕýÈ·µÄÊÇ£¨¡¡¡¡£©

• A£® ÔÚBµãµÄÓұ߼ÓËٶȴóСΪ$\frac{v_1}{{{t_2}-{t_1}}}$
• B£® СÎï¿éÔÚ¾­¹ýBµãºóÏòÓÒÔ˶¯µÄʱ¼äΪt₃-t₁
• C£® F₂µÄ´óСΪ$\frac{{m{v_1}}}{{{t_2}-{t_1}}}$
• D£® СÎï¿éÔÚBµãÓÒ±ßÔ˶¯µÄ×î´ó¾àÀëΪ$\frac{{v}_{1}{t}_{2}}{2}$

Answer 1

·ÖÎö ÓÉͼ¿ÉÖª£¬Ç°0-t₁ÄÚ£¬ÎïÌå×öÔȼÓËÙÖ±ÏßÔ˶¯£¬Æä¼ÓËÙ¶Èa₁=$\frac{{v}_{1}}{{t}_{1}}$£»¶øt₁ÖÁt₃ÎïÌåÏȼõËÙºó·´Ïò¼ÓËÙ£¬t₃ºó¼õËÙ£»Ôò¿ÉÅжϳöÎïÌåÔÚt₁ʱ¿ÌÇ¡ºÃ¾­¹ýMN£¬t₃Óֻص½MN£®s¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂɺÍÔ˶¯Ñ§¹«Ê½½áºÏ·ÖÎö£®

½â´ð ½â£ºA¡¢Í¼ÖÐt₁-t₃ʱ¼äÄÚÎï¿éÔÚMNµÄÓÒ·½Ô˶¯£¬¸ù¾ÝͼÏßµÄбÂʵÈÓÚ¼ÓËٶȵãºÎï¿éÔÚMNµÄÓÒ·½¼ÓËٶȴóСΪ£ºa₂=$\frac{v_1}{{{t_2}-{t_1}}}$£¬¹ÊAÕýÈ·£»
B¡¢ÔÚ0-t₁ʱ¼äÄÚ£¬Îï¿éÔÚMNµÄ×ó·½ÏòÓÒ×öÔȼÓËÙÔ˶¯£»ÔÚt₁-t₂ʱ¼äÄÚÔÚMNµÄÓÒ·½ÏòÓÒ×öÔȼõËÙÖ±ÏßÔ˶¯£¬ÔÚt₂-t₃ʱ¼äÄÚÔÚMNµÄÓÒ·½Ïò×ó×öÔȼÓËÙÖ±ÏßÔ˶¯£¬¸ù¾ÝÔ˶¯¹ý³ÌµÄ¶Ô³ÆÐÔµÃÖª£¬Ð¡Îï¿éÔÚ¾­¹ýBµãºóÏòÓÒÔ˶¯µÄʱ¼äΪt₂-t₁£®¹ÊB´íÎó£®
C¡¢ÔÚ0-t₁ʱ¼äÄÚ£¬¼ÓËٶȴóСΪa₁=$\frac{{v}_{1}}{{t}_{1}}$£¬ÓÉÅ£¶ÙµÚ¶þ¶¨ÂɵãºF₁=ma₁£¬F₂-F₁=ma₂£®½âµÃ£ºF₂=$\frac{m{v}_{1}}{{t}_{1}}$+$\frac{{m{v_1}}}{{{t_2}-{t_1}}}$£¬¹ÊC´íÎó£®
D¡¢Ð¡Îï¿éÔÚBµãÓÒ±ßÔ˶¯µÄ×î´ó¾àÀëµÈÓÚt₁-t₂ʱ¼äÄÚµÄλÒÆΪ£ºs=$\frac{{v}_{1}£¨{t}_{2}-{t}_{1}£©}{2}$£¬¹ÊD´íÎó£®
¹ÊÑ¡£ºA£®

µãÆÀ ±¾Ìâ½áºÏͼÏóÓëÅ£¶ÙÔ˶¯¶¨ÂÉ£¬Ó¦Í¨¹ýͼÏóµÃ³öÎïÌåµÄÔ˶¯Çé¿ö£¬ÔÙÓÉÅ£¶ÙµÚ¶þ¶¨Âɼ´¿ÉÇóµÃÊÜÁ¦Çé¿ö£®