關於 ticker-tapes 的一條MC...

小Ｇ

2008-06-05 12:12 am

In converting a tape into a tape chart, the tape is cut into lengths containing equal tick intervals.

Which of the following statements is / are correct?

(1) The length of each tape represents the average velocity within the time interval.
(2) The width of the tape represents the constant time interval.
(3) Joining the centres of the tops of the tape gives a displacement-time graph.

我選了(3)，但答案是(1)和(2)。
不知道怎麼解，麻煩把以上3項的statements都解一解，謝謝！

回答 (1)

hung yu

2008-06-05 5:56 pm

✔ 最佳答案

(1)
Length of each tape represents total displacement of object within a period of time. "Within the time interval" means that displacement per unit of time.
By v=s/t
Length of each tape within the time interval represents the average velocity

(2)
I guess it should be the length of the tape instead of the width. As the tape is cut into lengths containing equal tick intervals means measurement is taken regularly , e.g. 5 dots on a tape with 50Hz represent 0.1 s for each tape

(3)
Suppose displacement is constantly increasing, for the send point on graph, you should place the tape at 1st period above that of 2nd period to get a TOTAL displacement and so on.

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