Alex is standing on the side of an east-west direction, watching a car moving at 70km h^-1 due west. Nancy, driving east at a speed of 52km h^-1 , watches the same car. Taking the easterly direction as positive, what velocity of the car will Nancy measure?
thanks a lot~~
al relative velocity
2009-09-27 10:35 pm
回答 (1)
2009-09-27 11:14 pm
✔ 最佳答案
The relative velocity of the car with respect to Nancy= (-70 - 52) km/h = -122 km/h
i.e. 122 km/h in the west direction.
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