Question

1£®Èçͼ£¬ÔÚÀëƵ×Bµã¾àÀëΪlµÄÆÂÃæÉϵÄCµãÊúÖ±¹Ì¶¨Ò»¸ùÖ±¸ËAC£¬¸Ë¸ßÒ²ÊÇl£®¸ËµÄÉ϶˵½Æµ×BÖ®¼äÓÐÒ»¾øÔµ¹â»¬Ï¸¸Ë£®Ò»¸ö´øµçÁ¿Îª+q¡¢ÖÊÁ¿ÎªmµÄСÇò´©ÓÚϸ¸ËABÉÏ£¬´Ó¿¿½üAµã´¦Óɾ²Ö¹³ö·¢£®Õû¸öϵͳ´¦ÓÚˮƽÏòÓÒµÄÔÈÇ¿µç³¡ÖУ¬ÒÑÖª¡ÏCBA=37¡ã£¨sin37¡ã=0.6£¬cos37¡ã=0.8£©£¬ÇÒÒÑÖªÔ˶¯¹ý³ÌÖУ¬¸ËAB¶ÔСÇòµÄ×÷ÓÃÁ¦Ç¡ºÃΪÁ㣬µ±µØµÄÖØÁ¦¼ÓËÙ¶ÈΪg£¬Çó£º
£¨1£©µç³¡Ç¿¶ÈEµÄ´óС£»
£¨2£©Ð¡ÇòÔÚϸ¸ËÉÏÓÉAµã»¬Ðе½BµãËùÓõÄʱ¼ä£®

Answer 1

·ÖÎö £¨1£©¸ù¾ÝСÇòËùÊÜÖØÁ¦ºÍµç³¡Á¦µÄºÏÁ¦ÑظË×Ó·½Ïò£¬½áºÏƽÐÐËıßÐζ¨ÔòÇó³öµç³¡Ç¿¶ÈµÄ´óС£®
£¨2£©¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉÇó³öСÇòµÄ¼ÓËٶȣ¬½áºÏ¼¸ºÎ¹ØϵÇó³öλÒÆ£¬ÔËÓÃÔȱäËÙÖ±ÏßÔ˶¯µÄλÒÆʱ¼ä¹«Ê½Çó³öÔ˶¯µÄʱ¼ä£®

½â´ð ½â£º£¨1£©Ð¡ÇòÊܵ½ÖØÁ¦ºÍµç³¡Á¦×÷ÓÃÑظËAB×öÖ±ÏßÔ˶¯£¬ºÏÁ¦Ò»¶¨Ñظˣ¬¸ù¾ÝÁ¦µÄºÏ³É¼°¼¸ºÎ֪ʶµÃ£ºqE=mgtan37¡ã£¬
½âµÃ£ºE=$\frac{3mg}{4q}$£®
£¨2£©ÓÉÁ¦µÄºÏ³ÉºÍÅ£¶ÙµÚ¶þ¶¨Âɿɵãº
F_ºÏ=$\frac{mg}{cos37¡ã}=ma$                      ¢Ù
Óɼ¸ºÎ֪ʶ¿ÉÖª£º
x_AB=2lcos37¡ã                        ¢Ú
ÓÖÓÉÔ˶¯Ñ§¹«Ê½µÃ
${x}_{AB}=\frac{1}{2}a{t}^{2}$                                  ¢Û
ÁªÁ¢¢Ù¢Ú¢Û½âµÃ£º$t=\frac{8}{5}\sqrt{\frac{l}{g}}$£®
´ð£º£¨1£©µç³¡Ç¿¶ÈEµÄ´óСΪ$\frac{3mg}{4q}$£»
£¨2£©Ð¡ÇòÔÚϸ¸ËÉÏÓÉAµã»¬Ðе½BµãËùÓõÄʱ¼äΪ$\frac{8}{5}\sqrt{\frac{l}{g}}$£®

µãÆÀ ±¾Ì⿼²éÁËÅ£¶ÙµÚ¶þ¶¨ÂɺÍÔ˶¯Ñ§¹«Ê½µÄ×ÛºÏÔËÓã¬ÖªµÀ¼ÓËÙ¶ÈÊÇÁªÏµÁ¦Ñ§ºÍÔ˶¯Ñ§µÄÇÅÁº£®