urgen physics motions40points

👨🏻‍🏫 學術台其他 - 科學

[匿名]

2010-09-26 7:07 pm

圖片參考：http://imgcld.yimg.com/8/n/HA00178417/o/701009260039813873373680.jpg

(a)Does the carchange its travelling direction? Explain briefly

回答 (2)

[匿名]

2010-09-27 1:01 am

✔ 最佳答案

Yes, the car changes direction at t = 30 s.because its velocity changes from positive to negative, indicating a change in itstravelling direction.

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Ching Ming

2010-09-26 7:17 pm

是,因為速度正表示它向前行,速度負表示它向後行. (速度零當然是唔郁啦!)

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