ÌâÄ¿ÄÚÈÝ
ijÑо¿Ð¡×éΪ²âÁ¿Ò»¸öÒ£¿Øµç¶¯Ð¡³µµÄ¶î¶¨¹¦ÂÊ£¬½øÐÐÁËÈçÏÂʵÑ飺
¢ÙÓÃÌìƽ²â³öµç¶¯Ð¡³µµÄÖÊÁ¿Îª0.4kg£»
¢Ú½«µç¶¯Ð¡³µ¡¢Ö½´øºÍ´òµã¼ÆʱÆ÷°´ÈçͼËùʾ°²×°£»
¢Û½Óͨ´òµã¼ÆʱÆ÷£¨Æä´òµãÖÜÆÚΪ0.02s£©£»
¢Üʹµç¶¯Ð¡³µÒԶ¹¦ÂʼÓËÙÔ˶¯£¬´ïµ½×î´óËÙ¶ÈÒ»¶Îʱ¼äºó¹Ø±ÕС³µµçÔ´£¬´ýС³µ¾²Ö¹Ê±Ôٹرմòµã¼ÆʱÆ÷£¨ÉèС³µÔÚÕû¸ö¹ý³ÌÖÐС³µÓëÖ½´øËùÊܵÄ×èÁ¦ºã¶¨£©£®
ÔÚÉÏÊö¹ý³ÌÖУ¬´òµã¼ÆʱÆ÷ÔÚÖ½´øÉÏËù´òµÄ²¿·Öµã¼£ÈçͼËùʾ£¨ÒÑÖªÖ½´ø×ó¶ËÓëС³µÏàÁ¬£©£®
Çë·ÖÎöÖ½´øÊý¾Ý£¬ÊÔ¼ÆË㣨½á¹û¾ù±£ÁôÁ½Î»ÓÐЧÊý×Ö£©£º
£¨1£©µç¶¯Ð¡³µÔ˶¯µÃ×î´óËÙ¶ÈΪ
£¨2£©µç¶¯Ð¡³µ¹Ø±ÕµçÔ´ºó¼ÓËٶȴóСΪ
£¨3£©µç¶¯Ð¡³µµÃ¶î¶¨¹¦ÂÊΪ
¢ÙÓÃÌìƽ²â³öµç¶¯Ð¡³µµÄÖÊÁ¿Îª0.4kg£»
¢Ú½«µç¶¯Ð¡³µ¡¢Ö½´øºÍ´òµã¼ÆʱÆ÷°´ÈçͼËùʾ°²×°£»
¢Û½Óͨ´òµã¼ÆʱÆ÷£¨Æä´òµãÖÜÆÚΪ0.02s£©£»
¢Üʹµç¶¯Ð¡³µÒԶ¹¦ÂʼÓËÙÔ˶¯£¬´ïµ½×î´óËÙ¶ÈÒ»¶Îʱ¼äºó¹Ø±ÕС³µµçÔ´£¬´ýС³µ¾²Ö¹Ê±Ôٹرմòµã¼ÆʱÆ÷£¨ÉèС³µÔÚÕû¸ö¹ý³ÌÖÐС³µÓëÖ½´øËùÊܵÄ×èÁ¦ºã¶¨£©£®
ÔÚÉÏÊö¹ý³ÌÖУ¬´òµã¼ÆʱÆ÷ÔÚÖ½´øÉÏËù´òµÄ²¿·Öµã¼£ÈçͼËùʾ£¨ÒÑÖªÖ½´ø×ó¶ËÓëС³µÏàÁ¬£©£®
Çë·ÖÎöÖ½´øÊý¾Ý£¬ÊÔ¼ÆË㣨½á¹û¾ù±£ÁôÁ½Î»ÓÐЧÊý×Ö£©£º
£¨1£©µç¶¯Ð¡³µÔ˶¯µÃ×î´óËÙ¶ÈΪ
2.0
2.0
m/s£®£¨2£©µç¶¯Ð¡³µ¹Ø±ÕµçÔ´ºó¼ÓËٶȴóСΪ
2.5
2.5
m/s2£®£¨3£©µç¶¯Ð¡³µµÃ¶î¶¨¹¦ÂÊΪ
2.0
2.0
W£®·ÖÎö£º£¨1£©×îºóÔÈËÙµÄËٶȱãÊÇС³µÒԶ¹¦ÂÊÔ˶¯µÄ×î´óËٶȣ¬Óɴ˸ù¾ÝÖ½´ø¿ÉÇó³öС³µ×î´óËٶȣ®
£¨2£©ÀûÓÃÖð²î·¨¡÷x=aT2¿ÉÇó³öС³µµÄ¼ÓËٶȴóС£®
£¨3£©Ð¡³µÔÚĦ²ÁÁ¦Á¦×÷ÓÃϼõËÙÔ˶¯£¬¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉ¿ÉÇó³öĦ²ÁÁ¦µÄ´óС£¬µ±Ð¡³µ´ïµ½¶î¶¨¹¦ÂÊʱÓУºP=Fv=fvm£¬¾Ý´Ë¿ÉÇó³ö¶î¶¨¹¦ÂÊ´óС£®
£¨2£©ÀûÓÃÖð²î·¨¡÷x=aT2¿ÉÇó³öС³µµÄ¼ÓËٶȴóС£®
£¨3£©Ð¡³µÔÚĦ²ÁÁ¦Á¦×÷ÓÃϼõËÙÔ˶¯£¬¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉ¿ÉÇó³öĦ²ÁÁ¦µÄ´óС£¬µ±Ð¡³µ´ïµ½¶î¶¨¹¦ÂÊʱÓУºP=Fv=fvm£¬¾Ý´Ë¿ÉÇó³ö¶î¶¨¹¦ÂÊ´óС£®
½â´ð£º½â£º£¨1£©¸ù¾ÝÖ½´ø¿ÉÖª£¬µ±Ëù´òµÄµãµã¾à¾ùÔÈʱ£¬±íʾÎïÌåÔÈËÙÔ˶¯£¬´ËʱËÙ¶È×î´ó£¬¹ÊÓУº
vm=
=
=2.0m/s
£¨2£©£©´ÓÓÒµ½×óÉèÁ½¼ÆÊýµãÖ®¼äµÄ¾àÀë·Ö±ðΪx1¡¢x2¡¢x3¡¢x4¡¢x5¡¢x6£»
¼ÆÊýµãÖ®¼äµÄʱ¼ä¼ä¸ôΪ£ºT=0.04s£»
¸ù¾ÝÔȱäËÙÖ±ÏßÔ˶¯µÄÍÆÂÛ¹«Ê½¡÷x=aT2¿ÉÒÔÇó³ö¼ÓËٶȵĴóС£¬
µÃ£ºx4-x1=3a1T2
x5-x2=3a2T2
x6-x3=a3T2
ΪÁ˸ü¼Ó׼ȷµÄÇó½â¼ÓËٶȣ¬ÎÒÃǶÔÈý¸ö¼ÓËÙ¶Èȡƽ¾ùÖµ£¬ÓУº
a=
=
´úÈëÊý¾Ý½âµÃ£ºa=2.5m/s2£®
£¨3£©¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉС³µËùÊÜĦ²ÁÁ¦Îª£ºf=ma=£¨0.4¡Á2.5£©N=1.0N
µ±Ð¡³µ´ïµ½¶î¶¨¹¦ÂÊʱ£¬ÓУºF=f£¬Òò´Ë´ËʱÓУº
P=Fv=fvm=1.0¡Á2.0=2.0W£®
¹Ê´ð°¸Îª£º£¨1£©2.0£»£¨2£©2.5£»£¨3£©2.0£®
vm=
x |
t |
8.00cm |
0.04s |
£¨2£©£©´ÓÓÒµ½×óÉèÁ½¼ÆÊýµãÖ®¼äµÄ¾àÀë·Ö±ðΪx1¡¢x2¡¢x3¡¢x4¡¢x5¡¢x6£»
¼ÆÊýµãÖ®¼äµÄʱ¼ä¼ä¸ôΪ£ºT=0.04s£»
¸ù¾ÝÔȱäËÙÖ±ÏßÔ˶¯µÄÍÆÂÛ¹«Ê½¡÷x=aT2¿ÉÒÔÇó³ö¼ÓËٶȵĴóС£¬
µÃ£ºx4-x1=3a1T2
x5-x2=3a2T2
x6-x3=a3T2
ΪÁ˸ü¼Ó׼ȷµÄÇó½â¼ÓËٶȣ¬ÎÒÃǶÔÈý¸ö¼ÓËÙ¶Èȡƽ¾ùÖµ£¬ÓУº
a=
a1+a2+a3 |
3 |
(x4+x5+x6)-(x1+x2+x3) |
9T2 |
´úÈëÊý¾Ý½âµÃ£ºa=2.5m/s2£®
£¨3£©¸ù¾ÝÅ£¶ÙµÚ¶þ¶¨ÂÉС³µËùÊÜĦ²ÁÁ¦Îª£ºf=ma=£¨0.4¡Á2.5£©N=1.0N
µ±Ð¡³µ´ïµ½¶î¶¨¹¦ÂÊʱ£¬ÓУºF=f£¬Òò´Ë´ËʱÓУº
P=Fv=fvm=1.0¡Á2.0=2.0W£®
¹Ê´ð°¸Îª£º£¨1£©2.0£»£¨2£©2.5£»£¨3£©2.0£®
µãÆÀ£º±¾Ì⿼²éÁ˹¦¡¢¹¦ÂÊÎÊÌâÔÚʵ¼ÊÖÐÓ¦Óã¬ÒªÀí½â»ú³µµÄÁ½ÖÖÆô¶¯·½Ê½£¬ÕýÈ··ÖÎöÆô¶¯¹ý³ÌÖÐËٶȡ¢¼ÓËٶȡ¢¹¦Âʵȵı仯Çé¿ö£®
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿