An ultraviolet light wave has a wavelength of 300 nm and speed of 1.8 108 m/s through a transparent medium. What is the frequency of this wave in the medium? (1 nm = 10-9 m and c = 3.00 108 m/s)
a. 7.0 1014 Hz
c. 6.3 102 Hz
b. 6.0 1014 Hz
d. 10 1014 Hz
[Ques. 2] An airplane flying with a constant speed flies from a warm air mass into a cold air mass. The Mach number (the ratio of the speed of the airplane to the speed of sound) will:
a. increase.
c. stay the same.
b. decrease.
d. become unstable.
[Ques. 3] The human eye is sensitive to light with wavelength up to 750 nm. What is the frequency of radiation at this wavelength? (1 nm = 10-9 m and c = 3.00 108 m/s)
a. 8.5 108 Hz
c. 4.0 1014 Hz
b. 1.8 108 Hz
d. 7.7 1014 Hz
[Ques. 4] As a train starts from rest and then accelerates down the track, coming toward me faster and faster, the speed of the sound waves coming toward me will be:
a. slower than the normal speed of sound in air.
b. equal to the normal speed of sound in air.
c. some constant speed faster than the normal speed of sound in air.
d. faster and faster.
[Ques. 5] A radar pulse sent out to an airplane at a distance of 20.0 km will return as an echo to the source in what time interval? (c = 3.00 108 m/s)
a. 33.3 10-6 s
c. 66.7 10-6 s
b. 133 10-6 s
d. 0.0333 10-6 s
[Ques. 6] A 500-Hz whistle is moved toward a listener at a speed of 10.0 m/s. At the same time, the listener moves at a speed of 20.0 m/s in a direction toward the whistle. What is the apparent frequency heard by the listener? (The speed of sound is 340 m/s.)
a. 473 Hz
c. 533 Hz
b. 485 Hz
d. 545 Hz
[Ques. 7] A radio wave signal, which transmits at a frequency of 10.4 MHz, has what wavelength? (c = 3.00 108 m/s)
a. 28.8 m
c. 4.17 m
b. 2.4 10-2 m
d. 41.7 m
[Ques. 8] A sound source of frequency 1000 Hz moves at 40.0 m/s toward a listener who is at rest. What is the apparent frequency heard by the listener? (speed of sound = 340 m/s)
a. 853 Hz
c. 1130 Hz
b. 872 Hz
d. 1170 Hz
[Ques. 9] Glass panes are opaque to a certain type of radiation, which can cause sunburn. What type of radiation is it? This radiation is important in ozone layer reactions.
a. gamma
c. X-ray
b. ultraviolet
d. microwave
[Ques. 10] You stand by the railroad tracks as a train passes by. You hear a 950-Hz frequency when the train approaches, which changes to 820 Hz as it goes away. How fast is the train moving? The speed of sound in air is 340 m/s.
a. 14.0 m/s
c. 25.0 m/s
b. 20.0 m/s
d. 37.8 m/s
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