甲、乙、丙三辆小车同时、同地向同一方向运动,它们运动的图象如图7所示,由图象可知:运动速度相同的小车是______和______；经过5s,跑在最前面的小车是________.
甲和丙；乙
由第一个图象可知甲车做匀速直线运动，甲车的速度V甲=
m/s．由第二个图可知，乙车与丙车都做匀速直线运动，V乙=1m/s，V丙=2m/s，所以甲车与丙车的速度相同．经过t=5s甲车的路程S甲=V甲t=1m/s×5s=5m，乙车的路程s乙=V乙t=2m/s×5s=10m，故跑在前面的是乙车．
故答案为：甲和丙；乙．
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