更新1:
How are you finding the speed of sound in air?
What is the received sound frequency?
2021-04-16 11:50 pm
A bat at rest sends out ultrasonic sound waves at 49.5 kHz and receives them returned from an object moving directly away from it at 30.5 m/s .
回答 (2)
收錄日期: 2021-04-24 08:45:43
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20210416155043AAruzHU