Question

1£®ÎÒУ¸ßÈýѧÉú·Åѧºó´Ó½ÌÊÒµ½µÚһʳÌõÄ·³ÌԼΪ540m£®ÒÑÖª£º¸ßÈýѧÉúÕý³£¿ì²½×ßµÄËÙÂÊԼΪ1.5m/s£¬¸ßÈýѧÉú¿ìÅܵÄ×î´óËÙÂÊΪ9m/s£¬µ«Ö»Äܼá³Ö10s£®ÏÖÓÐÈýÃûͬѧ£¬ÒÔÈýÖÖ²»Í¬µÄ·½Ê½´Ó¸ßÈý½ÌÊÒÈ¥µÚһʳÌ㬲¢°ÑËûÃǵÄÔ˶¯ÊÓΪֱÏßÔ˶¯£®¼×ͬѧ´Ó¾²Ö¹¿ªÊ¼ÒÔ¼ÓËÙ¶Èa₁ÔȼÓËÙµ½×î´óËÙÂʺóÒÔ×î´óËÙÂÊÅÜÁË10s£¬½Ó×ÅÒÔ¼ÓËÙ¶Èa₁ÔȼõËÙµ½ËÙ¶ÈΪÁãÇ¡ºÃÄܵ½´ïµÚһʳÌã»ÒÒͬѧ´Ó¾²Ö¹¿ªÊ¼ÏÈÒÔ¼ÓËÙ¶Èa₂ÔȼÓËÙµ½×î´óËÙÂÊ£¬½Ó×ÅÒÔ¼ÓËÙ¶Èa₂ÔȼõËÙµ½ÁãÇ¡ºÃÄܵ½´ïµÚһʳÌã»±ûͬѧÒÔÕý³£¿ì²½×ßµÄËÙÂÊÔÈËÙµ½´ïµÚһʳÌã¬ÔòÏÂÁÐÓйØÈýλͬѧµÄ˵·¨ÕýÈ·µÄÊÇ£¨¡¡¡¡£©

• A£® ÈýͬѧÖУ¬ÒÒͬѧÏȵ½´ïµÚһʳÌÃ
• B£® ¼×ͬѧ±ÈÒÒͬѧÌáÇ°16s
• C£® ÈýͬѧÖУ¬×îÔçÓë×îÍíµ½´ïµÚһʳÌõÄʱ¼äÏà²î250s
• D£® ¼×¡¢ÒÒÁ½Í¬Ñ§µÄ¼ÓËÙ¶ÈÖ®±ÈΪ6£º5

Answer 1

·ÖÎö ¸ù¾ÝÔȱäËÙÖ±ÏßÔ˶¯µÄÔ˶¯Ñ§¹«Ê½·Ö±ðÇó³ö¼×ÒÒÁ½Í¬Ñ§µÄ¼ÓËٶȴóС£¬½áºÏËÙ¶Èʱ¼ä¹«Ê½Çó³öÔȼÓËÙºÍÔȼõËÙÔ˶¯µÄʱ¼ä£¬´Ó¶øµÃ³ö×Üʱ¼ä£®

½â´ð ½â£º¼×ͬѧ£¬ÔÈËÙÔ˶¯µÄλÒÆx₂=v_mt₂=9¡Á10m=90m£¬ÔȼÓËÙºÍÔȼõËÙÔ˶¯µÄλÒÆx₁=x₃=$\frac{540-90}{2}m=225m$£¬ÔòÔȼÓËÙºÍÔȼõËÙÖ±ÏßÔ˶¯µÄ¼ÓËٶȴóС${a}_{1}=\frac{{{v}_{m}}^{2}}{2{x}_{1}}=\frac{81}{2¡Á225}m/{s}^{2}$=0.18m/s²£®ÔȼÓËÙºÍÔȼõËÙÔ˶¯µÄʱ¼ä${t}_{1}={t}_{3}=\frac{{v}_{m}}{{a}_{1}}=\frac{9}{0.18}s=50s$£¬Ôò¼×µÄ×Üʱ¼ät=t₁+t₂+t₃=50+10+50s=110s£®
ÒÒͬѧ£¬ÔȼÓËÙºÍÔȼõËÙÖ±ÏßÔ˶¯µÄλÒÆ${x}_{1}¡ä={x}_{2}¡ä=\frac{540}{2}m=270m$£¬ÔòÔȼÓËÙºÍÔȼõËÙÔ˶¯µÄ¼ÓËٶȴóС${a}_{2}=\frac{{{v}_{m}}^{2}}{2{x}_{1}¡ä}=\frac{81}{540}$=0.15m/s²£¬ÔȼÓËÙºÍÔȼõËÙÔ˶¯µÄʱ¼ä${t}_{1}¡ä={t}_{2}¡ä=\frac{{v}_{m}}{{a}_{2}}=\frac{9}{0.15}s=60s$£¬ÔòÒÒµÄ×Üʱ¼ät¡ä=t₁¡ä+t₂¡ä=60+60s=120s£®
±ûͬѧÔ˶¯µÄ×Üʱ¼ä$t¡å=\frac{x}{v}=\frac{540}{1.5}s=360s$£¬ÓÉÉÏ¿ÉÖª£¬¼×ͬѧÏȵ½´ïµÚһʳÌ㬹ÊA´íÎó£®
¼×ͬѧ±ÈÒÒͬѧÌáÇ°µÄʱ¼ä¡÷t=120-110s=10s£¬¹ÊB´íÎó£®
ÈýͬѧÖУ¬×îÔçÓë×îÍíµ½´ïµÚһʳÌõÄʱ¼äÏà²î¡÷t=360-110s=250s£¬¹ÊCÕýÈ·£®
¼×ÒҵļÓËÙ¶ÈÖ®±Èa₁£ºa₂=0.18£º0.15=6£º5£¬¹ÊDÕýÈ·£®
¹ÊÑ¡£ºCD£®

µãÆÀ ½â¾ö±¾ÌâµÄ¹Ø¼üÀíÇå¼×ÒÒ±ûÈýͬѧÔÚÕû¸ö¹ý³ÌÖеÄÔ˶¯¹æÂÉ£¬½áºÏÔ˶¯Ñ§¹«Ê½Áé»îÇó½â£¬ÄѶȲ»´ó£®