ÌâÄ¿ÄÚÈÝ
7£®ÈçͼËùʾ£¬Ò»¡°V¡±ÐιìµÀPOQÓÉбÃæÓëˮƽÃ棨×ã¹»³¤£©ÔÚO´¦Æ½»¬Á¬½Ó¶ø³É£®ÔÚбÃæQOÉÏ£¬½«²»Í¬¸ß¶È´¦µÄA¡¢BÁ½Îï¿é£¨¾ùÊÓΪÖʵ㣩ͬʱÓɾ²Ö¹¿ªÊ¼ÊÍ·Å£¬ËüÃÇÒÔ¹²Í¬µÄ¼ÓËÙ¶Èa1=5m/s2ÑØбÃæ¹ìµÀÏ»¬£¬µ±ËüÃÇͨ¹ýOµã½øÈëˮƽ¹ìµÀºó£¬½«»á×öÔȼõËÙÖ±ÏßÔ˶¯£¬ÇÒ¼ÓËٶȴóС¾ùΪa2=1m/s2£®ÒÑÖªA¡¢BÁ½Îï¿é³õʼλÖþàбÃæµ×¶ËOµÄ¾àÀë·Ö±ðΪLA=6.4m£¬LB=0.9m£¬ÇÒÁ½Îï¿éͨ¹ýO´¦¹ý³ÌµÄËٶȴóС²»±ä£¬Ç󣺣¨1£©Îï¿éA»¬µ½OµãʱÓëÎï¿éB¼äµÄ¾àÀëL£»
£¨2£©Îï¿éA´Ó¿ªÊ¼ÊÍ·ÅÖÁ×·ÉÏÎï¿éBËùÓõÄʱ¼ät£®
·ÖÎö £¨1£©ÀûÓÃλÒÆʱ¼ä¹«Ê½ÇóµÃABÔÚбÃæÉÏÔ˶¯µÄʱ¼ä¼°µ½´ïOµãµÄËٶȣ¬ÀûÓÃˮƽÃæÉϵÄʱ¼äºÍÔ˶¯Ñ§¹«Ê½¼´¿ÉÇóµÃ
£¨2£©ÏÈÅжϳöA×·ÉÏBʱ£¬BÊÇ·ñ´¦ÓÚ¾²Ö¹×´Ì¬£¬È»ºóÔÙÀûÓÃÔ˶¯Ñ§¹«Ê½ÇóµÃʱ¼ä
½â´ð ½â£º»¬¿éAÏ»¬µ½OµãµÄʱ¼äΪtA£¬Ôò${L}_{A}=\frac{1}{2}{{a}_{1}t}_{A}^{2}$
${t}_{A}=\sqrt{\frac{2{L}_{A}}{{a}_{1}}}=\sqrt{\frac{2¡Á6.4}{5}}s=1.6s$
»¬¿éAÏ»¬µ½OµãµÄʱ¼äΪtB£¬Ôò${L}_{B}=\frac{1}{2}{at}_{B}^{2}$
½âµÃ${t}_{B}=\sqrt{\frac{2{L}_{B}}{{a}_{1}}}=\sqrt{\frac{2¡Á0.9}{5}}s=0.6s$
Bµ½´ïOµãµÄËÙ¶ÈvB=a1tB=3m/s
µ±Aµ½´ïOµãºó£¬BÔÚˮƽÃæÉÏ»¬ÐеÄʱ¼ä¡÷t=tA-tB=1s
»¬ÐеľàÀë$x={v}_{B}¡÷t-\frac{1}{2}{a}_{2}£¨¡÷t£©^{2}$=$3¡Á1-\frac{1}{2}¡Á1¡Á{1}^{2}m=2.5m$
£¨2£©AÏ»¬µ½OµãËÙ¶ÈvA=a1tA=8m/s
B¼õËÙµ½ÁãËùÐèʱ¼ä$t=\frac{{v}_{B}}{{a}_{2}}=\frac{3}{1}s=3s$
3sÄÚBͨ¹ýµÄλÒÆ$x¡ä=\frac{{v}_{B}^{2}}{2{a}_{2}}=\frac{9}{2¡Á1}m=4.5m$
´ËʱAÔÚˮƽÃæÉÏÔ˶¯2s£¬Í¨¹ýµÄλÒÆ$x¡å={v}_{A}t-\frac{1}{2}{a}_{2}{t}^{2}=14m$£¬¹ÊÔÚB¾²Ö¹Ç°A×·ÉÏB
¹Ê${v}_{A}{t}_{Ë®}-\frac{1}{2}{{a}_{2}t}_{Ë®}^{2}={v}_{B}£¨¡÷t+{t}_{Ë®}£©-\frac{1}{2}$${a}_{2}£¨¡÷t+{t}_{Ë®}£©^{2}$
½âµÃ$t=\frac{5}{12}s$
¹ÊÎï¿éA´Ó¿ªÊ¼ÊÍ·ÅÖÁ×·ÉÏÎï¿éBËùÓõÄʱ¼äΪ£ºt×Ü=tA+t=2.02s
´ð£º£¨1£©Îï¿éA»¬µ½OµãʱÓëÎï¿éB¼äµÄ¾àÀëLΪ2.5m£»
£¨2£©Îï¿éA´Ó¿ªÊ¼ÊÍ·ÅÖÁ×·ÉÏÎï¿éBËùÓõÄʱ¼äΪ2.02s
µãÆÀ ±¾Ì⿼²é×·»÷ÎÊÌ⣬ץסÔÚˮƽÃæÉÏAÔÚ×·ÉÏBʱ£¬A±ÈBÉÙÔ˶¯1s£¬È»ºóÀûÓúÃÔ˶¯Ñ§¹«Ê½£¬¹Ø¼üÊÇÅжÏA×·ÉÏBʱ£¬BÊÇ·ñ¾²Ö¹£®
A£® | ÎïÌåA¿ÉÄÜÖ»Êܵ½Èý¸öÁ¦µÄ×÷Óà | |
B£® | ÎïÌåAÒ»¶¨Êܵ½ÁËËĸöÁ¦µÄ×÷Óà | |
C£® | ÎïÌåAÊܵ½µÄ»¬¶¯Ä¦²ÁÁ¦´óСΪFcos¦Á | |
D£® | ÎïÌåA¶ÔˮƽµØÃæµÄѹÁ¦´óСһ¶¨ÎªFsin¦Á |
A£® | Õý£¬BµÄÓÒ±ß0.4m´¦ | B£® | Õý£¬BµÄ×ó±ß0.2m´¦ | ||
C£® | ¸º£¬AµÄ×ó±ß0.2m´¦ | D£® | ¸º£¬AµÄÓÒ±ß0.2m´¦ |
A£® | µØÃæ¶Ôµ¯»ÉµÄ³åÁ¿µÈÓÚmv | B£® | µØÃæ¶Ôµ¯»ÉµÄ³åÁ¿µÈÓÚmv+mgt | ||
C£® | µØÃæ¶Ôµ¯»ÉµÄ³åÁ¿µÈÓÚmgt | D£® | µØÃæ¶Ôµ¯»ÉµÄ³åÁ¿µÈÓÚ0 |
A£® | ÎïÌåµÄÖÊÁ¿Îª$\frac{10}{9}$kg | |
B£® | 2¡«6sÄÚÀÁ¦×öµÄ¹¦Îª40J | |
C£® | ºÏÍâÁ¦ÔÚ0¡«6sÄÚ×öµÄ¹¦Óë0¡«2sÄÚ×öµÄ¹¦ÏàµÈ | |
D£® | ÎïÌåËùÊÜ»¬¶¯Ä¦²ÁÁ¦µÄ´óСΪ5N |
£¨1£©ÓйزÙ×÷ºÍ²âÁ¿µÄ˵·¨ÖÐÕýÈ·µÄÊÇBC
A£®ÏÈÊÍ·ÅС³µ£¬ÔÙ½ÓͨµçÔ´£¬µ±Ð¡³µµ½´ï»¬ÂÖÇ°¼°Ê±ÓÃÊÖ°´×¡Ëüºó¹Ø±ÕµçÔ´
B£®¿ªÊ¼ÊÍ·ÅС³µÇ°£¬Ó¦Ê¹Ð¡³µ¿¿½ü´òµã¼ÆʱÆ÷
C£®²âÁ¿Ê±Ó¦ÉáÈ¥Ö½´øÉϵÄÃܼ¯µã£¬È»ºóÑ¡È¡¼ÆÊýµã
D£®±ØÐëÿ5¸ö´òÓ¡µãÉèÒ»¸ö¼ÆÊýµã
£¨2£©ÊµÑéºó£¬¼×ͬѧѡÔñÁËÒ»Ìõ½ÏΪÀíÏëµÄÖ½´ø£¬²âÁ¿Êý¾Ýºó£¬Í¨¹ý¼ÆËãµÃµ½ÁËС³µÔ˶¯¹ý³ÌÖи÷¼Æʱʱ¿ÌµÄËÙ¶ÈÈç±í¸ñËùʾ£®
λÖñàºÅ | 0 | 0.1 | 0.2 | 0.3 | 0.4 |
ʱ¼ät/s | 0 | 0.1 | 0.2 | 0.3 | 0.4 |
ËÙ¶Èv/m•s-1 | 0.42 | 0.67 | 0.92 | 1.16 | 1.42 |
£¨3£©Ä³Í¬Ñ§ÀûÓôòµã¼ÆʱÆ÷Ëù¼Ç¼µÄÖ½´øÀ´Ñо¿Ð¡³µ×ö ÔȱäËÙÖ±ÏßÔ˶¯µÄÇé¿ö£¬ÊµÑéÖлñµÃÒ»ÌõÖ½´ø£¬Èçͼ£¬ÆäÖÐÁ½ÏàÁÚ¼ÆÊýµã¼äÓÐÁ½¸öµãδ»³ö£®ÒÑÖªËùÓõçÔ´µÄƵÂÊΪ50Hz£¬Ôò´òBµãʱС³µÔ˶¯µÄËٶȴóСvB=1.32m/s£¬Ð¡³µÔ˶¯µÄ¼ÓËٶȴóСa=8.33m/s2£®£¨¼ÆËã½á¹û±£Áô3λÓÐЧÊý×Ö£©
A£® | ÖØÁ¦ÊÆÄܲ»±ä£¬¶¯ÄÜÔö¼Ó£¬»úеÄܼõÉÙ | |
B£® | ÖØÁ¦ÊÆÄܼõÉÙ£¬¶¯Äܲ»±ä£¬»úеÄÜÔö¼Ó | |
C£® | ÖØÁ¦ÊÆÄܼõÉÙ£¬¶¯ÄÜÔö¼Ó£¬»úеÄܼõÉÙ | |
D£® | ÖØÁ¦ÊÆÄܼõÉÙ£¬¶¯ÄÜÔö¼Ó£¬»úеÄܲ»±ä |
A£® | ´óСºÍ·½Ïò¶¼Ôڱ仯µÄµçÁ÷½Ð×öÕñµ´µçÁ÷ | |
B£® | ´óСºÍ·½Ïò¶¼×öÖÜÆÚÐÔѸËٱ仯µÄµçÁ÷½ÐÕñµ´µçÁ÷ | |
C£® | Óɵç¸ÐÏßȦºÍµç×èÆ÷×é³ÉµÄµç·Äܹ»²úÉúÕñµ´µçÁ÷ | |
D£® | Óɵç¸ÐÏßȦºÍµçÈÝÆ÷×é³ÉµÄ»Ø·Äܹ»²úÉúÕñµ´µçÁ÷ |