ÌâÄ¿ÄÚÈÝ
Ò»Á¾¿Í³µ´ÓƽÌÁ¿ªÍù¶¼ÔÈ£¬Æ½ÌÁÖÁÄ«³åµÄ·³ÌΪ36km£¬ÓÉÓÚ·¿ö²»ºÃ£¬ÎªÁËʹ³µ°²È«ÐÐÊ»£¬´ÓƽÌÁµ½Ä«³åÓÃʱ48·ÖÖÓ£¬µ½Ä«³åºó£¬¼ÝʻԱΪÁ˽ÚԼʱ¶ø¸Ä×߸ßËÙ¹«Â·£¬ÒÔ75km/hµÄËÙ¶ÈÐÐÊ»ÍêºóÃæ30kmµÄ·³Ì¼´¿Éµ½´ï¶¼ÔÈ£®ÎÊ£º
£¨1£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½Ä«³åµÄƽ¾ùËÙ¶ÈÊǶàÉÙkm/h£¿
£¨2£©ÕâÁ¾¿Í³µ´ÓÄ«³åµ½¶¼ÔÈÐèÒª¶àÉÙСʱ£¿
£¨3£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½¶¼ÔÈµÄÆ½¾ùËÙ¶ÈÊǶàÉÙkm/h£¿
£¨1£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½Ä«³åµÄƽ¾ùËÙ¶ÈÊǶàÉÙkm/h£¿
£¨2£©ÕâÁ¾¿Í³µ´ÓÄ«³åµ½¶¼ÔÈÐèÒª¶àÉÙСʱ£¿
£¨3£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½¶¼ÔÈµÄÆ½¾ùËÙ¶ÈÊǶàÉÙkm/h£¿
ÒÑÖª£ºs1=36km t1=48min=0.8h v2=75km/h s2=30km
Ç󣺣¨1£©v1=£¿£¨2£©t2=£¿£¨3£©v=£¿
£¨1£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½Ä«³åµÄƽÔÈËÙ¶ÈÊÇv1=
=
=45km/h£»
£¨2£©ÕâÁ¾¿Í³µ´ÓÄ«³åµ½¶¼ÔÈÐèÒªt2=
=
=0.4h£»
£¨3£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½¶¼ÔÈµÄÆ½¾ùËÙ¶ÈÊÇv=
=
=
=55km/h£®
´ð£º£¨1£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½Ä«³åµÄƽÔÈËÙ¶ÈÊÇ45km/h£»
£¨2£©ÕâÁ¾¿Í³µ´ÓÄ«³åµ½¶¼ÔÈÐèÒª0.4h£»
£¨3£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½¶¼ÔÈµÄÆ½¾ùËÙ¶ÈÊÇ55km/h£®
Ç󣺣¨1£©v1=£¿£¨2£©t2=£¿£¨3£©v=£¿
£¨1£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½Ä«³åµÄƽÔÈËÙ¶ÈÊÇv1=
| s1 |
| t1 |
| 36km |
| 0.8h |
£¨2£©ÕâÁ¾¿Í³µ´ÓÄ«³åµ½¶¼ÔÈÐèÒªt2=
| s2 |
| v2 |
| 30km |
| 75km/h |
£¨3£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½¶¼ÔÈµÄÆ½¾ùËÙ¶ÈÊÇv=
| s |
| t |
| s1+s2 |
| t1+t2 |
| 36km+30km |
| 0.8h+0.4h |
´ð£º£¨1£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½Ä«³åµÄƽÔÈËÙ¶ÈÊÇ45km/h£»
£¨2£©ÕâÁ¾¿Í³µ´ÓÄ«³åµ½¶¼ÔÈÐèÒª0.4h£»
£¨3£©ÕâÁ¾¿Í³µ´ÓƽÌÁµ½¶¼ÔÈµÄÆ½¾ùËÙ¶ÈÊÇ55km/h£®
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿