ÌâÄ¿ÄÚÈÝ
8£®ÈçͼËùʾ£¬Ò»¸öÖÊÁ¿Îª1kgµÄú¿é´Ó¹â»¬ÇúÃæÉϸ߶ÈH=1.25m´¦ÎÞ³õËÙÊÍ·Å£¬µ½´ïµ×¶Ëʱˮƽ½øÈëˮƽ´«ËÍ´ø£¬´«ËÍ´øÓÉÒ»µç¶¯»úÇý¶¯×ÅÔÈËÙÏò×óת¶¯£¬ËÙÂÊΪ3m/s£®ÒÑ֪ú¿éÓë´«ËÍ´ø¼äµÄ¶¯Ä¦²ÁÒòÊý¦Ì=0.2£®Ãº¿é³åÉÏ´«ËÍ´øºó¾ÍÒÆ×߹⻬ÇúÃ森£¨gÈ¡10m/s2£©£®£¨1£©ÈôÁ½Æ¤´øÂÖÖ®¼äµÄ¾àÀëÊÇ6m£¬Ãº¿é½«´ÓÄÄÒ»±ßÀ뿪´«ËÍ´ø£¿
£¨2£©ÈôƤ´øÂÖ¼äµÄ¾àÀë×ã¹»´ó£¬´Óú¿é»¬Éϵ½À뿪´«ËÍ´øµÄÕû¸ö¹ý³ÌÖУ¬ÓÉÓÚú¿éºÍ´«ËÍ´ø¼äµÄĦ²Á¶ø²úÉúµÄ»®ºÛ³¤¶ÈÓж೤£¿Ä¦²ÁÁ¦¶Ôú¿é×öµÄ¹¦Îª¶à´ó£¿
·ÖÎö £¨1£©¸ù¾Ý»úеÄÜÊغ㶨ÂÉÇó³öú¿éµ½´ï×îµÍµãµÄËٶȣ¬¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉÇó³öú¿éÔÚ´«ËÍ´øÉÏÔȼõËÙÖ±ÏßÔ˶¯µÄ¼ÓËٶȣ¬½áºÏËÙ¶ÈλÒƹ«Ê½Çó³öËٶȼõΪÁãµÄλÒÆ£¬Óë´«ËÍ´øµÄ³¤¶È±È½Ï£¬ÅжÏú¿é´ÓÄÄÒ»±ßÀ뿪´«ËÍ´ø£®
£¨2£©ÎïÌ廬ÉÏ´«ËÍ´øºóÏòÓÒ×öÔȼõËÙÔ˶¯Ö±µ½ËÙ¶ÈΪÁ㣬ºóÏò×ó×öÔȼÓËÙÔ˶¯£¬Ö±µ½ËÙ¶ÈÓë´«ËÍ´øËÙ¶ÈÏàµÈºóÓë´«ËÍ´øÏà¶Ô¾²Ö¹£¬¸ù¾ÝÔ˶¯Ñ§¹«Ê½Çó³öÎï¿éµÄλÒÆ´óСºÍ´«ËÍ´øµÄλÒÆ´óС£¬´Ó¶øµÃ³öÏà¶ÔλÒƵĴóС£¬½áºÏ¶¯Äܶ¨ÀíÇó³öĦ²ÁÁ¦¶Ôú¿é×ö¹¦µÄ´óС£®
½â´ð ½â£º£¨1£©Ãº¿é´ÓÇúÃæÉÏÏ»¬Ê±»úеÄÜÊغ㣬ÓÐ$mgH=\frac{1}{2}mv_0^2$
½âµÃú¿é»¬µ½µ×¶ËʱµÄËÙ¶È${v_0}=\sqrt{2gH}=5m/s$
ÒÔµØÃæΪ²ÎÕÕϵ£¬Ãº¿é»¬ÉÏ´«ËÍ´øºóÏòÓÒ×öÔȼõËÙÔ˶¯Ö±µ½ËÙ¶ÈΪÁ㣬ÆÚ¼äú¿éµÄ¼ÓËٶȴóСºÍ·½Ïò¶¼²»±ä£¬¼ÓËٶȴóСΪ$a=\frac{F_f}{M}=¦Ìg=2m/{s^2}$£¬
ú¿é´Ó»¬ÉÏ´«ËÍ´øµ½Ïà¶ÔµØÃæËٶȼõСµ½Á㣬¶ÔµØÏòÓÒ·¢ÉúµÄλÒÆΪ${s_1}=\frac{0-v_0^2}{-2a}=\frac{{0-{5^2}}}{-4}m=6.25m£¾6m$£¬Ãº¿é½«´ÓÓÒ±ßÀ뿪´«ËÍ´ø£®
£¨2£©ÒÔµØÃæΪ²Î¿¼Ïµ£¬ÈôÁ½Æ¤´øÂÖ¼äµÄ¾àÀë×ã¹»´ó£¬Ôòú¿é»¬ÉÏ´«ËÍ´øºóÏòÓÒ×öÔȼõËÙÔ˶¯Ö±µ½ËÙ¶ÈΪÁ㣬ºóÏò×ó×öÔȼÓËÙÔ˶¯£¬Ö±µ½ËÙ¶ÈÓë´«ËÍ´øËÙ¶ÈÏàµÈºóÓë´«ËÍ´øÏà¶Ô¾²Ö¹£¬´Ó´«ËÍ´ø×ó¶ËµôÏ£¬ÆÚ¼äú¿éµÄ¼ÓËٶȴóСºÍ·½Ïò¶¼²»±ä£¬¼ÓËٶȴóСΪ$a=\frac{F_f}{M}=¦Ìg=2m/{s^2}$£®
È¡ÏòÓÒΪÕý·½Ïò£¬Ãº¿é·¢ÉúµÄλÒÆΪ${s_1}=\frac{v_1^2-v_0^2}{2¡Á£¨-a£©}=\frac{{{3^2}-{5^2}}}{2¡Á£¨-2£©}=4m$£¬
ú¿éÔ˶¯µÄʱ¼äΪ$t=\frac{{v}_{1}-{v}_{0}}{-a}=\frac{-3-5}{-2}s=4s$£¬
Õâ¶Îʱ¼äÄÚƤ´øÏò×óÔ˶¯µÄλÒÆ´óСΪs2=vt=3¡Á4m=12m
ú¿éÏà¶ÔÓÚ´«ËÍ´ø»¬ÐеľàÀëΪ¡÷s=s1+s2=16m£¬
¸ù¾Ý¶¯Äܶ¨ÀíµÃ£¬${W}_{f}=\frac{1}{2}m{v}^{2}-\frac{1}{2}m{{v}_{0}}^{2}$=$\frac{1}{2}¡Á1¡Á£¨9-25£©J=-8J$£®
´ð£º£¨1£©Ãº¿é½«´ÓÓÒ±ßÀ뿪´«ËÍ´ø£®
£¨2£©Ãº¿éºÍ´«ËÍ´ø¼äµÄĦ²Á¶ø²úÉúµÄ»®ºÛ³¤¶ÈΪ16m£¬Ä¦²ÁÁ¦¶Ôú¿é×öµÄ¹¦Îª-8J£®
µãÆÀ ±¾Ì⿼²éÁ˶¯Äܶ¨Àí¡¢Å£¶ÙµÚ¶þ¶¨ÀíºÍÔ˶¯Ñ§¹«Ê½µÄ×ÛºÏÔËÓã¬×ÛºÏÐÔ½ÏÇ¿£¬¹Ø¼üÀíÇåú¿éÔÚÕû¸ö¹ý³ÌÖеÄÔ˶¯¹æÂÉ£¬½áºÏÅ£¶ÙµÚ¶þ¶¨ÂɺÍÔ˶¯Ñ§¹«Ê½×ÛºÏÇó½â£®
A£® | ǽ¶ÔBµÄ×÷ÓÃÁ¦¼õС | B£® | B¶ÔAµÄ×÷ÓÃÁ¦Ôö´ó | ||
C£® | µØÃæ¶ÔAµÄÖ§³ÖÁ¦²»±ä | D£® | ˮƽÍâÁ¦FÔö´ó |
A£® | Ö»ÓеçºÉÁ¿ºÜСµÄ´øµçÌå²ÅÄÜ¿´³ÉÊǵãµçºÉ | |
B£® | ËùÓдøµçÌåµÄµçºÉÁ¿¿ÉÒÔ²»µÈÓÚÔªµçºÉµÄÕûÊý±¶ | |
C£® | Ħ²ÁÆðµç˵Ã÷ͨ¹ý×ö¹¦¿ÉÒÔ´´Ôì³öµçºÉ | |
D£® | ¸ÐÓ¦Æðµç˵Ã÷µçºÉ¿ÉÒÔ´ÓÎïÌåµÄÒ»²¿·ÖתÒƵ½ÁíÒ»¸ö²¿·Ö |
A£® | Öʵ㵥λʱ¼äÄÚËÙÂʵı仯Á¿×ÜÊDz»±ä | |
B£® | ÖʵãËٶȵķ½Ïò×ÜÊÇÓë¸ÃºãÁ¦µÄ·½ÏòÏàͬ | |
C£® | Öʵã¼ÓËٶȵķ½Ïò×ÜÊÇÓë¸ÃºãÁ¦µÄ·½ÏòÏàͬ | |
D£® | ÖʵãËٶȵķ½Ïò²»¿ÉÄÜ×ÜÊÇÓë¸ÃºãÁ¦µÄ·½Ïò´¹Ö± |
A£® | ÎïÌåÔ˶¯µÄ¼ÓËٶȵÈÓÚ0£¬¶øËÙ¶ÈÈ´²»µÈÓÚ0£® | |
B£® | ÎïÌå¾ßÓÐÏò¶«µÄ¼ÓËٶȣ¬¶øËٶȷ½ÏòÈ´ÏòÎ÷ | |
C£® | ÎïÌå×öÖ±ÏßÔ˶¯£¬ºóÒ»½×¶ÎµÄ¼ÓËٶȱÈÇ°Ò»½×¶ÎС£¬µ«ËÙ¶ÈÈ´±ÈÇ°Ò»¶Î´ó | |
D£® | Á½ÎïÌåÏà±È£¬Ò»¸öÎïÌåµÄËٶȱ仯±È½Ï¿ì£¬¶ø¼ÓËÙ¶ÈÈ´±È½ÏС |
£¨1£©Èçͼ1ËùʾÊÇһλͬѧÔÚʵÑéÖÐÈ¡µÃÁ˼¸Ìõ½ÏΪÀíÏëµÄÖ½´ø£¬ÆäÖÐÿÁ½¸ö¼ÆÊýµãÖ®¼ä»¹ÓÐ4¸ö¼Æʱµãδ»³ö£¬¼´ÏàÁÚÁ½¼ÆÊýµã¼äµÄʱ¼ä¼ä¸ôΪ0.1s£¬½«Ã¿ÌõÖ½´øÉϵļÆÊýµã·Ö±ð¼ÇΪ0¡¢1¡¢2¡¢3¡¢4¡¢5¡ÈçÏÂͼËùʾ£¬ÓÉÓÚ²»Ð¡ÐÄ£¬aÖ½´øÔÚ¿ªÊ¼²¿·ÖºÍºó°ë²¿·Ö¶¼±»Ëº¶ÏÁË£¬Ôò¸ù¾Ýͼ¿ÉÖª£¬ÔÚb¡¢c¡¢dÈý¶ÎÖ½´øÖУ¬bÊÇ´ÓÖ½´øaÉÏ˺ϵÄÄDz¿·Ö£»´òaÖ½´øʱ£¬ÎïÌåµÄ¼ÓËٶȴóСÊÇ0.6m/s2£¬¼ÆÊýµã2¶ÔÓ¦µÄËٶȴóСÊÇ0.3m/s£®£¨±¾Ð¡Ìâ½á¹û¾ù±£ÁôһλÓÐЧÊý×Ö£©
£¨2£©ÁíһλͬѧµÃµ½Ò»ÌõÓõç»ð»¨¼ÆʱÆ÷´òϵÄÖ½´øÈçͼ2Ëùʾ£¬²¢ÔÚÆäÉÏÈ¡ÁËA¡¢B¡¢C¡¢D¡¢E¡¢F¡¢G 7¸ö¼ÆÊýµã£¬Ã¿Îå¸ö¼ÆʱµãÈ¡Ò»¸ö¼ÆÊýµã£¬µç»ð»¨¼ÆʱÆ÷½Ó220V¡¢50Hz½»Á÷µçÔ´£®
¢ÙÉèµç»ð»¨¼ÆʱÆ÷µÄÖÜÆÚΪT£¬¼ÆËãFµãµÄ˲ʱËÙ¶ÈvFµÄ¹«Ê½ÎªvF=$\frac{{d}_{6}-{d}_{4}}{2T}$£»
¢ÚËû¾¹ý²âÁ¿²¢¼ÆËãµÃµ½µç»ð»¨¼ÆʱÆ÷ÔÚ´òB¡¢C¡¢D¡¢E¡¢F¸÷µãʱÎïÌåµÄ˲ʱËÙ¶ÈÈçÏÂ±í£®ÒÔAµã¶ÔÓ¦µÄʱ
¿ÌΪt=0£¬ÊÔÔÚͼ3Ëùʾ×ø±êϵÖкÏÀíµØÑ¡Ôñ±ê¶È£¬×÷³öv-tͼÏ󣬲¢ÀûÓøÃͼÏóÇó³öÎïÌåµÄ¼ÓËÙ¶Èa=0.4m/s2£»
¶ÔÓ¦µã | B | C | D | E | F |
Ëٶȣ¨m/s£© | 0.141 | 0.180 | 0.218 | 0.262 | 0.301 |