https://www.sendspace.com/file/u22ixf
A strobe photo of a pendulum which swings through half a cycle from A to B. The photo is taken with a stroboscopic lamp of frequency 10 Hz.
What is the average speed of the bob ?
Tks
Pendulum motion
2015-04-28 10:42 pm
回答 (2)
2015-04-28 11:38 pm
✔ 最佳答案
Where is the strobo photo?2015-04-28 17:08:53 補充：
Since the stroboscopic lamp has a frequency of 10 Hz, time interval between two sucessive strobo images = 1/10 s = 0.1 s
Hence, time taken from the bob to trave from A to B
= 0.1 x 6 s = 0.6 s
2015-04-28 17:12:25 補充：
(cont'd)...
70 degrees = 70 x pi/180 radians, where pi = 3.14159...
Distance travelled between A and B = 0.4 x (70 x pi/180) m = 0.4887 m
Average speed of bob = 0.4887/0.6 m/s = 0.8145 m/s
2015-04-29 12:58 am
收錄日期: 2021-04-15 19:15:41
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20150428000051KK00042