Physics: Resonance in Strings and the Doppler Effect
By C Colwell
Common Information/Directions for the next 2 problems:
While standing near a railroad crossing, a person hears a distant train horn. According to the train's engineer, the frequency emitted by the horn is 440 hz. The train is traveling at 20.0 m/sec and the speed of sound is 346 m/sec.
1.
Which of the following combinations correctly describes the frequencies heard by the bystander at the train crossing?
2.
True or False: If the 440 hz horn was instead a stationary crossing alarm and the "bystander" had been a passenger on a train moving at 20.0 m/sec, he would hear the same apparent frequencies calculated in the previous question.
Common Information/Directions for the next 2 problems:
A person is driving at 15 m/sec toward a blowing factory whistle (f = 800 hz). The speed of sound is 340.6 m/sec.
3.
What frequency does this person hear?
4.
What frequency would he hear once he has passed the factory if he continues at the same speed?
Common Information/Directions for the next 6 problems:
A wave pulse can travel 5 meters along a given rope in 0.25 seconds. The rope is initially being shaken to form a standing wave pattern that displays 4 loops.
5.
True or False: The wave is traveling at 1.25 m/sec.
6.
This wave pattern would be called the
7.
What is the wavelength of the waveform resonating in this standing wave pattern?
8.
True or False: The rope is being shaken at a frequency of 16 hz to produce this 4-loop standing wave pattern.
9.
The fundamental wavelength for standing waves along this rope would be
10.
Which of the following resonance states could NOT be formed along this rope?