A person is standing 1 km away from a source of sound. If the velocity of sound in the medium is 340 m/s, then calculate the number of oscillations (approximately) that the sound wave makes before it reaches that person. The frequency of the sound is 500 Hz.
1470
Given,
Distance between source and observer,d=1 km=1000 m
Velocity of sound,v =340 ms−1
Frequency of sound ,f=500 Hz
Time taken by the sound wave to reach the observer from the source = dv=1000340=2.94 sec
Now, the frequency of sound wave is 500 Hz, i.e.
In one second, the wave makes 500 oscillations
In 2.94 seconds, the sound wave will make (2.94 x 500) oscillations.
Thus, the correct answer = 2.94 x 500 = 1470 oscillations.