一小汽车以30m/s速度匀速行驶，司机突然发现前方有紧急情况，0.6s后开始刹车，又经4.4s滑行52m，车停止，则从发现情况到车停止的平均速度为 ______m/s．
0.6s汽车行驶的路程为s=vt=30m/s×0.6s=18m，
从发现情况到车停止的平均速度为v均=
=s总 t总
=18m+52m 0.6s+4.4s
=14m/s，70m 5s
故答案为：14．
The sun is shining and it’s very hot. 31 many people don’t want to go out after 32 . Mrs. West has to(不得不) 33 her father at the airport. Her father doesn’t feel well, he wants to see a 34 in the city hospital. Now she’s 35 in the street. There 36 no trees and she feels very 37 . But she’s too 38 and can’t walk fast(快). Suddenly she finds(发现) a 39 walking behind her. She gets angry and her face turns red. “Why are you walking 40 me, boy?” She asks strictly. “It’s cooler”. The boy answers.
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