✔ 最佳答案
The displacement is given by the function
圖片參考:
http://upload.wikimedia.org/math/7/a/c/7ac3484c2b42686da65e26d84c792894.png
We then differentiate once to get an expression for the velocity at any time.
圖片參考:
http://upload.wikimedia.org/math/f/c/d/fcd0e5911ca23e8d4642647d8106d340.png
And once again to get the acceleration at a given time.
圖片參考:
http://upload.wikimedia.org/math/c/c/8/cc8db2e97f088a95810e52488cd18560.png
These results can of course be simplified, giving us an expression for acceleration in terms of displacement.
圖片參考:
http://upload.wikimedia.org/math/6/0/3/603d83916e2771ef99de50a13bce1173.png
SO
the maximum acceleration of the needle
=(2*PI*2.55)^2*1.27
=326 cm/s2
答案是C