Question

9£®ÈçͼËùʾ£¬ÖÊÁ¿M=10kgµÄС³µ·ÅÔڹ⻬ˮƽÃæÉÏ£¬ÔÚС³µ×ó¶Ë¼ÓһˮƽÍÆÁ¦F=10N£¬µ±Ð¡³µÏòÓÒÔ˶¯µÄËٶȴﵽ1.4m/sʱ£¬ÔÚС³µÓÒ¶ËÇáÇáµØ·ÅÒ»¸ö´óС²»¼Æ¡¢ÖÊÁ¿m=2kgµÄСÎï¿é£®Ð¡Îï¿éÓëС³µ¼äµÄ¶¯Ä¦²ÁÒòÊý¦Ì=0.2£¬Ð¡³µ×ã¹»³¤£®gÈ¡10m/s²£¬Ôò£º
£¨1£©Ð¡Îï¿é¸Õ·ÅÉÏС³µÊ±£¬Ð¡Îï¿é¼°Ð¡³µµÄ¼ÓËٶȸ÷Ϊ¶à´ó£»
£¨2£©¾­¶à³¤Ê±¼äÁ½ÕßËÙ¶ÈÏàͬ£¿¹²Í¬Ëٶȶà´ó£»
£¨3£©´ÓСÎï¿é·ÅÉÏС³µ¿ªÊ¼£¬¾­¹ýt=1.6s£¬Ð¡Îï¿éͨ¹ýµÄλÒÆ´óСΪ¶àÉÙ£¿

Answer 1

·ÖÎö £¨1£©Ð¡Îï¿é¸Õ·ÅÉÏС³µÊ±£¬¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉ·Ö±ðÇó³öСÎï¿é¼°Ð¡³µµÄ¼ÓËٶȣ»
£¨2£©¸ù¾ÝËÙ¶Èʱ¼ä¹ØϵÇó³öËÙ¶ÈÏàµÈµÄʱ¼ä¼°¹²Í¬Ëٶȣ»
£¨3£©Îï¿éÏÈ×öÔȼÓËÙÔ˶¯£¬µ±ËٶȺÍС³µËÙ¶ÈÏàµÈºóÕûÌåÒÔÏàͬµÄ¼ÓËÙ¶È×öÔȼÓËÙÔ˶¯£¬Çó³öÇ°1s£¨¼´ËÙ¶ÈÏàµÈÇ°£©µÄλÒÆ£¬ÓÉÅ£¶ÙµÚ¶þ¶¨ÂÉÇó³öÕûÌå¼ÓËٶȣ¬¸ù¾ÝλÒÆʱ¼ä¹ØϵÇó³öºó0.6sµÄλÒÆ£¬×îºóÇó×ÜλÒÆ£»

½â´ð ½â£º£¨1£©Ð¡Îï¿é¸Õ·ÅÉÏС³µÊ±£¬¶ÔСÎï¿éÓУº
$¦Ìmg=m{a}_{1}^{\;}$
µÃ${a}_{1}^{\;}=2m/{s}_{\;}^{2}$
¶ÔС³µÓÐ
$F-¦Ìmg=M{a}_{2}^{\;}$
µÃ${a}_{2}^{\;}=0.6m/{s}_{\;}^{2}$
£¨2£©É辭ʱ¼ät¶þÕߴﹲͬËÙ¶Èv
¶ÔСÎï¿é
$v={a}_{1}^{\;}t$
¶ÔС³µ
$v={v}_{0}^{\;}+{a}_{2}^{\;}t$
ÁªÁ¢´úÈëÊý¾ÝµÃ£º
v=2m/s
t=1s
£¨3£©Ð¡Îï¿éÔÚµÚÒ»ÃëÄÚ·¢ÉúµÄλÒÆ
${s}_{1}^{\;}=\frac{0+v}{2}•t$
´ïµ½¹²Í¬ËÙ¶Èʱ£¬ÉèÎï¿é¡¢Ð¡³µÕûÌå¼ÓËÙ¶ÈΪa£¬Ôò
F=£¨M+m£©a
µÃ$a=\frac{5}{6}m/{s}_{\;}^{2}£¼{a}_{1}^{\;}=2m/{s}_{\;}^{2}$
¹ÊÎï¿é¡¢Ð¡³µÕûÌå¼ÓËÙ
СÎï¿éÔÚºó0.6sÄÚ¼ÓËÙ·¢ÉúµÄλÒÆ
${s}_{2}^{\;}=v{t}_{2}^{\;}+\frac{1}{2}a{t}_{2}^{2}$
¾­¹ý${t}_{0}^{\;}=1.6s$СÎï¿éͨ¹ýµÄ×ÜλÒÆ´óСΪ
$s={s}_{1}^{\;}+{s}_{2}^{\;}$
´úÈëÊý¾ÝµÃ
s=2.35m
´ð£º£¨1£©Ð¡Îï¿é¸Õ·ÅÉÏС³µÊ±£¬Ð¡Îï¿é2$m/{s}_{\;}^{2}$¼°Ð¡³µµÄ¼ÓËÙ¶ÈΪ$0.6m/{s}_{\;}^{2}$£»
£¨2£©¾­1sʱ¼äÁ½ÕßËÙ¶ÈÏàͬ£¬¹²Í¬ËÙ¶È2m/s
£¨3£©´ÓСÎï¿é·ÅÉÏС³µ¿ªÊ¼£¬¾­¹ýt=1.6s£¬Ð¡Îï¿éͨ¹ýµÄλÒÆ´óСΪ2.35m

µãÆÀ ±¾ÌâÎïÌå¶à¡¢¹ý³Ì¶à£¬¹Ø¼ü·ÖÏà¶Ô»¬¶¯¹ý³ÌºÍÎÞÏà¶Ô»¬¶¯¹ý³ÌÌÖÂÛ£¬ÒªÃ÷È·ÊÜÁ¦Çé¿öºÍÔ˶¯¹æÂÉ£¬½áºÏÅ£¶ÙµÚ¶þ¶¨ÂɺÍÔ˶¯Ñ§¹«Ê½ÁÐʽÇó½â£¬²»ÄÑ£®