The alarm of a vehicle parked next to a straight horizontal road goes off, emitting
sound with a wavelength of 0,34 m. A patrol car is moving at a constant speed on the
same road. The driver of the patrol car hears a sound with a frequency of 50 Hz lower
than the sound emitted by the alarm. Take the speed of sound in air as 340 m∙s-1.
6.1 State the Doppler effect in words. (2)
6.2 Is the patrol car driving TOWARDS or AWAY FROM the parked vehicle?
Give a reason for the answer. (2)
6.3 Calculate the frequency of the sound emitted by the alarm. (3)
6.4 The patrol car moves a distance of x metres in 10 seconds. Calculate the
distance x. (6)
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