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標題:
Physics question!!!
發問:
In Figure a French submarine and a U.S. submarine move toward each other during maneuvers in motionless water in the North Atlantic. The French sub moves at speed vF = 55.00 km/h, and the U.S. sub at vUS = 70.00 km/h. The French sub sends out a sonar signal (sound wave in water) at 1100 Hz. Sonar waves... 顯示更多 In Figure a French submarine and a U.S. submarine move toward each other during maneuvers in motionless water in the North Atlantic. The French sub moves at speed vF = 55.00 km/h, and the U.S. sub at vUS = 70.00 km/h. The French sub sends out a sonar signal (sound wave in water) at 1100 Hz. Sonar waves travel at 5490 km/h. (a) What is the signal's frequency as detected by the U.S. sub? (b) What frequency is detected by the French sub in the signal reflected back to it by the U.S.sub? pic: http://upload.lsforum.net/users/public/e29071002q74.png
最佳解答:
55 km/h = 15.28 m/s 70 km/h = 19.44 m/s 5490 km/h = 1525 m/s (a) Use the Doppler Effect formula Frequency of signal obsered by the US submarine = 1100 x [(1525 + 19.44)/(1525 - 15.28)] m/s = 1125 Hz (b) The reflected wave is of frequency 1125 Hz Use the Doppler Effect formula again, Frequency of signal observed by the French submarine = 1125 x [(1525 + 15.28)/(1525 - 19.44)] Hz = 1151 Hz
其他解答:6A560DB68EC65D60
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