ÌâÄ¿ÄÚÈÝ
¡¾ÌâÄ¿¡¿Í¼(a)ΪһÁмòгºá²¨ÔÚt£½0.1 sʱ¿ÌµÄ²¨ÐÎͼ£¬PÊÇƽºâλÖÃΪx£½1 m´¦µÄÖʵ㣬QÊÇƽºâλÖÃΪx£½4 m´¦µÄÖʵ㣬ͼ(b)ΪÖʵãQµÄÕñ¶¯Í¼Ïó£¬ÔòÏÂÁÐ˵·¨ÕýÈ·µÄÊÇ(¡¡¡¡)
A. ¸Ã²¨µÄÖÜÆÚÊÇ0.1 s
B. ¸Ã²¨µÄ´«²¥ËÙ¶ÈΪ40 m/s
C. ¸Ã²¨ÑØxÖáµÄ¸º·½Ïò´«²¥
D. t£½0.1 sʱ£¬ÖʵãQµÄËٶȷ½ÏòÏòÏÂ
E. ´Ót£½0.1 sµ½ t£½0.25 s£¬ÖʵãPͨ¹ýµÄ·³ÌΪ30 cm
¡¾´ð°¸¡¿BCD
¡¾½âÎö¡¿ÓÉͼÒÒÖª¸Ã²¨µÄÖÜÆÚÊÇ0.20s£®¹ÊA´íÎó£®Óɼ×ͼ֪²¨³¤¦Ë=8m£¬Ôò²¨ËÙΪ£º £¬¹ÊBÕýÈ·£®ÔÚt=0.10sʱ£¬ÓÉÒÒͼ֪ÖʵãQÕýÏòÏÂÔ˶¯£¬¸ù¾Ý²¨ÐÎƽÒÆ·¨¿ÉÖª¸Ã²¨ÑØxÖḺ·½Ïò´«²¥£¬¹ÊCDÕýÈ·£®¸Ã²¨ÑØxÖḺ·½Ïò´«²¥£¬´ËʱPµãÕýÏòÉÏÔ˶¯£®´Ót=0.10sµ½=0.25s¾¹ýµÄʱ¼äΪ¡÷t=0.15s=
T£¬ÓÉÓÚt=0.10sʱ¿ÌÖʵãP²»ÔÚƽºâλÖûò²¨·å¡¢²¨¹È´¦£¬ËùÒÔÖʵãPͨ¹ýµÄ·³Ì²»ÊÇ3A=30cm£¬¹ÊE´íÎó£»¹ÊÑ¡BCD.
µã¾¦:±¾ÌâÓÐÒ»¶¨µÄ×ÛºÏÐÔ£¬¿¼²ìÁ˲¨¶¯ºÍÕñ¶¯Í¼ÏóÎÊÌ⣬¹Ø¼üÊÇ»á¸ù¾ÝÕñ¶¯Çé¿öÀ´Åжϲ¨µÄ´«²¥·½Ïò£¬×¥×¡Õñ¶¯Í¼ÏóºÍ²¨¶¯Í¼ÏóÖ®¼äµÄÄÚÔÚÁªÏµ£®ÒªÖªµÀÖʵã×ö¼òгÔ˶¯Ê±£¬Ö»ÓÐÔÚƽºâλÖûò²¨·å¡¢²¨¹È´¦µÄÖʵ㣬ÔÚÖÜÆÚÄÚÕñ¶¯µÄ·³Ì²ÅÊÇ3A£®
