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çï¼è®¾æ£å¸¸è¡é©¶è¿ç¨ï¼å é度è¿ç¨ä¸ºè¡é©¶è·¯ç¨ä¸ºS1ï¼åéè¡é©¶è·¯ç¨ä¸ºS2ï¼ååéè¿ç¨è¡é©¶è·¯ç¨ä¸ºS3ï¼è¡é©¶æ»è·¯ç¨ä¸ºSï¼è®¾æ£å¸¸è¡é©¶è¿ç¨ä¸åéè¡é©¶çæ¶é´ä¸ºT2ã
设æç¹è¡é©¶è¿ç¨ï¼å é度è¿ç¨ä¸ºè¡é©¶è·¯ç¨ä¸ºS'1ï¼åéè¡é©¶è·¯ç¨ä¸ºS'2ï¼ååéè¿ç¨è¡é©¶è·¯ç¨ä¸ºS'3ï¼è¡é©¶æ»è·¯ç¨å为Sï¼è®¾æç¹è¡é©¶è¿ç¨ä¸åéè¡é©¶çæ¶é´ä¸ºTâ2ã
åAãB两ç«ä¹é´çè·ç¦»ä¸ºSï¼S=S1+S2+S3=Sâ1+Sâ2+Sâ3ï¼S1=S3ï¼Sâ1=Sâ3ã
1ãå解ååä½ï¼v1=50m/sï¼v2=60m/sã
2ãæ£å¸¸è¡é©¶å éå°180km/héè¦çæ¶é´T1=v1/a1=50/0.5=100s
æç¹è¡é©¶å éå°216km/héè¦çæ¶é´Tâ1=v2/a2=60/0.5=120s
T'2=T2-(120-100)*2-3*60
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S1=S3=V0t+1/2at^2=0+0.5*0.5*100*100=2500m
Sâ1=Sâ3=V0t+1/2at^2=0+0.5*0.5*120*120=3600m
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å½¢æ¯è¾ï¼S=S1+S2+S3=Sâ1+Sâ2+Sâ3
2500+50*T2+2500=3600+60*T'2+3600
2500+50*T2+2500=3600+60*[T2-(120-100)*2-3*60]+3600
计ç®å¾ï¼T2=1100s
åï¼S=S1+S2+S3= 2500+50*(T2+3*60)+2500=5000+50*1100=60000m
AãB两ç«ä¹é´çè·ç¦»=60000m
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