Q: A train sounds its horn as it approaches an intersection. The
A train sounds its horn as it approaches an intersection. The horn can just be heard at a level of 50. dB by an observer 10 km away. (a) What is the average power generated by the horn? (b) What inten...
See AnswerQ: An outside loudspeaker (considered a small source) emits sound waves
An outside loudspeaker (considered a small source) emits sound waves with a power output of 100 W. (a) Find the intensity 10.0 m from the source. (b) Find the intensity level in decibels at that dista...
See AnswerQ: Show that the difference in decibel levels β1 and β 2 of
Show that the difference in decibel levels β1 and β 2 of a sound source is related to the ratio of its distances r1 and r2 from the receivers by the formula
See AnswerQ: A skyrocket explodes 100 m above the ground (Fig. P14
A skyrocket explodes 100 m above the ground (Fig. P14.24). Three observers are spaced 100 m apart, with the first (A) directly under the explosion. (a) What is the ratio of the sound intensity heard b...
See AnswerQ: A baseball hits a car, breaking its window and triggering its
A baseball hits a car, breaking its window and triggering its alarm which sounds at a frequency of 1250 Hz. What frequency is heard by a boy on a bicycle riding away from the car at 6.50 m/s?
See AnswerQ: A train is moving past a crossing where cars are waiting for
A train is moving past a crossing where cars are waiting for it to pass. While waiting, the driver of the lead car becomes sleepy and rests his head on the steering wheel, unintentionally activating t...
See AnswerQ: A commuter train passes a passenger platform at a constant speed of
A commuter train passes a passenger platform at a constant speed of 40.0 m/s. The train horn is sounded at its characteristic frequency of 320. Hz. (a) What overall change in frequency is detected by...
See AnswerQ: An airplane traveling at half the speed of sound emits a sound
An airplane traveling at half the speed of sound emits a sound of frequency 5.00 kHz. At what frequency does a stationary listener hear the sound (a) As the plane approaches? (b) After it passes?
See AnswerQ: Two trains on separate tracks move toward each other. Train 1
Two trains on separate tracks move toward each other. Train 1 has a speed of 1.30 x 102 km/h; train 2, a speed of 90.0 km/h. Train 2 blows its horn, emitting a frequency of 5.00 x 102 Hz. What is the...
See AnswerQ: On a hot summer day, the temperature of air in Arizona
On a hot summer day, the temperature of air in Arizona reaches 114°F. What is the speed of sound in air at this temperature?
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