Question

18£®¼ÙÆÚÖУ¬Ð¡Ã÷³Ë×ø»ð³µÍâ³öÂÃÓΣ¬µ±»ð³µÔÚÒ»¶ÎƽֱµÄ¹ìµÀÉÏÔȼÓËÙÐÐʻʱ£¬ËûÓÃÉí±ßµÄÆ÷²Ä²âÁ¿»ð³µµÄ¼ÓËٶȣ®Ð¡Ã÷µÄ²âÁ¿¹ý³ÌÈçÏ£ºËûÒ»±ß¿´×Å´°Íâ¼ä¸ôΪ100mµÄ·±ê£¬Ò»±ßÓÃÊÖ±í¼Ç¼×Åʱ¼ä£®Ëû¹Û²âµ½ËûËùÔڵijµÏá´Ó¾­¹ýµÚÒ»¸ù·±êµ½¾­¹ýµÚ¶þ¸ù·±êµÄʱ¼ä¼ä¸ôΪ10s£¬´Ó¾­¹ýµÚÒ»¸ù·±êµ½¾­¹ýµÚÈý¸ù·±êµÄʱ¼ä¼ä¸ôΪ16s£®ÇëÄã¸ù¾ÝËûµÄ²âÁ¿Çé¿ö£¬Çó£º
£¨1£©»ð³µµÄ¼ÓËٶȴóС£»
£¨2£©»ð³µ¾­¹ýµÚÈý¸ù·±êʱµÄËٶȴóС£®

Answer 1

·ÖÎö £¨1£©´ÓµÚÒ»¸ù·±êµ½µÚ¶þ¸ù·±ê¼°´ÓµÚÒ»¸ù·±êµ½µÚÈý¸ù·±ê·Ö±ð¸ù¾ÝλÒÆʱ¼äµÄ¹ØϵʽÁÐʽ£¬ÁªÁ¢¿ÉÒÔÇóµÃ¼ÓËٶȵĴóС£»
£¨2£©¸ù¾ÝËÙ¶Èʱ¼ä¹Øϵʽ¿ÉÒԵû𳵾­¹ýµÚÈý¸ù·±êʱµÄËٶȵĴóС£®

½â´ð ½â£º£¨1£©Éè»ð³µ¾­¹ýµÚÒ»¸ù·±êʱËÙ¶ÈΪv₀£¬¼ÓËÙ¶ÈΪa£¬ÓÉÔ˶¯Ñ§¹«Ê½$x={v_0}{t_1}+\frac{1}{2}at_1^2$£¬$2x={v_0}{t_2}+\frac{1}{2}at_2^2$£¬½«x=100m£¬t₁=10s£¬t₂=16s´úÈë¿ÉµÃ
$100={v}_{0}^{\;}¡Á10+\frac{1}{2}a¡Á£¨10£©_{\;}^{2}$¢Ù
$200={v}_{0}^{\;}¡Á16+\frac{1}{2}a¡Á£¨16£©_{\;}^{2}$¢Ú
½âµÃ£º${v}_{0}^{\;}=\frac{25}{6}m/s$£¬$a=\frac{5}{6}m/{s}_{\;}^{2}$
¹Ê»ð³µµÄ¼ÓËÙ¶ÈΪ$\frac{5}{6}m/{s}_{\;}^{2}$
£¨2£©ÓÉËٶȹ«Ê½£ºv_t=v₀+at₂£¬
´úÈëÊý¾Ý£º${v}_{t}^{\;}=\frac{25}{6}+\frac{5}{6}¡Á16=\frac{105}{6}m/s=17.5m/s$
´ð£º£¨1£©»ð³µµÄ¼ÓËٶȴóС$\frac{5}{6}m/{s}_{\;}^{2}$£»
£¨2£©»ð³µ¾­¹ýµÚÈý¸ù·±êʱµÄËٶȴóС17.5m/s£®

µãÆÀ ±¾Ìâ¾ÍÊǶÔλÒƺÍËٶȹ«Ê½µÄ¿¼²é£¬ÕÆÎÕס¹«Ê½Êǹؼü£¬¸ù¾Ý¹«Ê½Ö±½ÓÇó½â¼´¿É£¬ÄѶȲ»´ó