我既問題係, 點解吾可以假設果個星球係一個吾會動既source, 而地球就遠離緊依個source呢?
更新1:
當然做左假設...兩條公式吾一樣之餘, 而且推導左出泥既結果確實係有分別.
關於都卜勒效應(中六課程)
2010-03-21 4:13 am
a-level物理書入面話, 要計算一個星球既遠離地球既相對速度, 就要假設地球係一個吾會動既observer觀測緊個星球.
我既問題係, 點解吾可以假設果個星球係一個吾會動既source, 而地球就遠離緊依個source呢?
我既問題係, 點解吾可以假設果個星球係一個吾會動既source, 而地球就遠離緊依個source呢?
回答 (4)
2010-03-21 7:14 am
✔ 最佳答案
The formula for Doppler effect in light is the same for either source (of light) or observer is moving.The formula is, df/f = v/c
where df is the change of frequency
f is the original frequency
v is the the speed of the source or observer
c is the speed of light (= 3 x 10^8 m/s)
You could not differentiate between the motion of the source and the observer.
2010-03-21 9:07 am
you cannot use the formula for sound
see
http://en.wikipedia.org/wiki/Relativistic_Doppler_effect
sound needs a medium but light does not
see
http://en.wikipedia.org/wiki/Relativistic_Doppler_effect
sound needs a medium but light does not
2010-03-21 5:22 am
其實呢....係方便計算ga 姐
你試想想, 如果兩個星期一齊動一個係v1 , 一個係v2 ,
錦相對speed 係 | v1-v2|
好na , 如果只係一個動 , 錦你就可以直接量度到 | v1-v2| ge 相對speed, 而唔駛度兩個錦煩la ,
化簡左個實驗 ,錦米可以避免左d error law ,
而且, 其實係一樣ga , 角色調換is ok
你試想想, 如果兩個星期一齊動一個係v1 , 一個係v2 ,
錦相對speed 係 | v1-v2|
好na , 如果只係一個動 , 錦你就可以直接量度到 | v1-v2| ge 相對speed, 而唔駛度兩個錦煩la ,
化簡左個實驗 ,錦米可以避免左d error law ,
而且, 其實係一樣ga , 角色調換is ok
2010-03-21 4:34 am
應該可以，因為世事無絕對嗎，但既然係假設，你就依照人地假設做一次，然後再依你嘅假設做多一次，睇睇喺咪相同，呢啲先係科學精神。
收錄日期: 2021-04-29 17:34:37
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100320000051KK01483