posted by guli on .
Ige confused, the truck driver sound the horn of the truck, which has a frequency of 260HZ. The speed of sound in air is 340m/s. an observer hears the sound while traveling in a bus toward the truck at a speed of 30m/s.
a) what is the wavelength of the sound the whisle emits?
b)calculat the speed of sound relative to the observer on the bus when the truck is 1)approching the truck and 2)when the moving away from the truck.
c) calculate the frequency of the sound heard by the observer in b-1 and b-2.
a) wavelength = (sound speed)/(frequency) = 1.308 m
b1) 340+30 m/s = ___
b2) 340-30 m/s = ___
c1) Doppler-shifted frequency
= relative speed of sound/(wavelength)
= 370/1.308 = ___ Hz
c2) 310/1.308 = ___ Hz