Question

4£®ÈçͼËùʾ£¬Çã½ÇΪ¦ÈµÄ×ã¹»´ó¹â»¬¾ØÐÎбÃæABCD£¬ABˮƽÇÒ´¹Ö±ÓÚAD£¬AD³¤L=12m£¬Ò»Ð¡ÇòÔÚбÃæÉÏ´ÓбÃ涥¶ËAµãÒÔÒ»¶¨µÄ³õËÙ¶Èv₀ÑØABÅ׳ö£¬Ð¡ÇòÑØAB·½ÏòµÄλÒÆͼÏóºÍÑØAD·½ÏòµÄËÙ¶ÈͼÏóÈçͼËùʾ£®gÈ¡10m/s²£¬£¨sin53¡ã=0.8£¬cos53¡ã=0.6£©£¬Çó£º

£¨1£©Ð±ÃæµÄÇã½Ç¦ÈµÄ´óС
£¨2£©Ð¡ÇòÑØбÃ滬µ½DC±ßʱˮƽλÒÆs£»
£¨3£©Ð¡Çòµ½´ïбÃæµ×±ßDCʱµÄËٶȴóС£®

Answer 1

·ÖÎö £¨1£©½«Ð¡ÇòµÄÔ˶¯·Ö½âΪÑØAB·½ÏòºÍƽÐÐAD·½Ïò£¬¸ù¾ÝƽÐÐAD·½ÏòµÄËÙ¶Èʱ¼äͼÏߵóö¼ÓËٶȵĴóС£¬¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉÇó³öбÃæµÄÇã½Ç£®
£¨2£©¸ù¾ÝADµÄ³¤¶ÈÇó³öÀàƽÅ×Ô˶¯µÄʱ¼ä£¬¸ù¾Ý³õËٶȺÍʱ¼ä¹«Ê½Çó³öˮƽλÒÆ£®
£¨3£©¸ù¾ÝËÙ¶Èʱ¼ä¹«Ê½Çó³öµ½´ïµ×¶ËƽÐÐÓÚAD·½ÏòµÄËٶȣ¬½áºÏƽÐÐËıßÐζ¨ÔòÇó³öµ½´ïµ×±ßʱµÄËٶȴóС£®

½â´ð ½â£º£¨1£©ÔÚƽÐÐAD·½ÏòÉÏ£¬¸ù¾ÝËÙ¶Èʱ¼äͼÏßÖª£¬¼ÓËÙ¶Èa=$\frac{6}{1}m/{s}^{2}=6m/{s}^{2}$£¬
¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨Âɵã¬a=gsin¦È£¬
½âµÃ¦È=37¡ã£®
£¨2£©ÓÉx-tͼÏßÖª£¬Ð¡ÇòµÄ³õËÙ¶È${v}_{0}=\frac{5}{1}m/s=5m/s$£¬
¸ù¾ÝL=$\frac{1}{2}a{t}^{2}$µÃ£¬t=$\sqrt{\frac{2L}{a}}=\sqrt{\frac{2¡Á12}{6}}s=2s$£¬
ÔòˮƽλÒÆs=v₀t=5¡Á2m=10m£®
£¨3£©Ð¡Çòµ½´ïµ×¶ËʱÑØAD·½ÏòµÄËÙ¶Èv_y=at=6¡Á2m/s=12m/s£¬
¸ù¾ÝƽÐÐËıßÐζ¨ÔòÖª£¬Ð¡Çòµ½´ïµ×¶ËµÄËÙ¶Èv=$\sqrt{{{v}_{0}}^{2}+{{v}_{y}}^{2}}=\sqrt{25+144}$m/s=13m/s£®
´ð£º£¨1£©Ð±ÃæµÄÇã½Ç¦ÈµÄ´óСΪ37¡ã£»
£¨2£©Ð¡ÇòÑØбÃ滬µ½DC±ßʱˮƽλÒÆsΪ10m£»
£¨3£©Ð¡Çòµ½´ïбÃæµ×±ßDCʱµÄËٶȴóСΪ13m/s£®

µãÆÀ ½â¾ö±¾ÌâµÄ¹Ø¼üÕÆÎÕ´¦ÀíÀàƽÅ×Ô˶¯µÄ·½·¨£¬×¥×¡µÈʱÐÔ£¬½áºÏÅ£¶ÙµÚ¶þ¶¨ÂɺÍÔ˶¯Ñ§¹«Ê½×ÛºÏÇó½â£¬ÄѶÈÖеȣ®