ÌâÄ¿ÄÚÈÝ
¡¾ÌâÄ¿¡¿ÈçͼËùʾ£¬°×É«´«ËÍ´ø±£³Öv0£½10 m/sµÄËÙ¶ÈÄæʱÕëת¶¯£¬ÏÖ½«Ò»ÖÊÁ¿Îª0.4kgµÄú¿éÇá·ÅÔÚ´«ËÍ´øµÄA¶Ë£¬Ãº¿éÓë´«ËÍ´ø¼ä¶¯Ä¦²ÁÒòÊý¦Ì£½0.5£¬´«ËÍ´øABÁ½¶Ë¾àÀëx£½16 m£¬´«ËÍ´øÇã½ÇΪ370£¬(sin370=0.6 £¬cos370=0.8£¬g£½10 m/s2)£¨ £©
A. ú¿é´ÓA¶ËÔ˶¯µ½B¶ËËù¾ÀúµÄʱ¼äΪ2s
B. ú¿é´ÓA¶ËÔ˶¯µ½B¶ËÏà¶Ô´«ËÍ´øµÄÏà¶ÔλÒÆΪ6m
C. ú¿é´ÓA¶ËÔ˶¯µ½B¶Ë»³öµÄºÛ¼£³¤¶ÈΪ5m
D. ú¿é´ÓA¶ËÔ˶¯µ½B¶ËĦ²Á²úÉúµÄÈÈÁ¿Îª6.4J
¡¾´ð°¸¡¿AC
¡¾½âÎö¡¿Ãº¿é¸Õ·ÅÉÏ´«ËÍ´øʱµÄ¼ÓËٶȴóСΪ£ºa1£½ =gsin37¡ã+¦Ìgcos37¡ã=6+0.5¡Á8m/s2=10m/s2£¬Ôòú¿éËٶȴﵽ´«ËÍ´øËٶȵÄʱ¼äΪ£º
£¬Î»ÒÆΪ£º
£¬Ãº¿éËٶȴﵽ´«ËÍ´øËٶȺóµÄ¼ÓËÙ¶ÈΪ£ºa2£½
=gsin37¡ã-¦Ìgcos37¡ã=6-4m/s2=2m/s2£¬¸ù¾Ýxx1£½v0t2+
a2t22´úÈëÊý¾Ý½âµÃ£ºt2=1s£¬Ôòú¿é´ÓA¶ËÔ˶¯µ½B¶ËËù¾ÀúµÄʱ¼äΪ£ºt=t1+t2=2s£¬¹ÊAÕýÈ·¡£Îï¿éËٶȴﵽ´«ËÍ´øʱ£¬Ïà¶ÔλÒÆ´óС¡÷x1=v0t1-x1=10-5m=5m£¬Îï¿éËٶȴﵽ´«ËÍ´øºóÏà¶ÔλÒƵĴóС¡÷x2=x-x1-v0t2=11-10¡Á1m=1m£¬ÔòÏà¶ÔλÒƵĴóС¡÷x=¡÷x1-¡÷x2=5-1m=4m£¬¹ÊB´íÎó¡£Áôϵĺۼ£³¤¶È¡÷x¡ä=¡÷x1=5m£¬¹ÊCÕýÈ·¡£Ä¦²Á²úÉúµÄÈÈÁ¿Q=¦Ìmgcos37¡ã¡÷x1+¦Ìmgcos37¡ã¡÷x2=0.5¡Á4¡Á0.8¡Á5+0.5¡Á4¡Á0.8¡Á1J=9.6J£¬¹ÊD´íÎó¡£¹ÊÑ¡AC¡£
![](http://thumb2018.1010pic.com/images/loading.gif)