Answer:
Infrasonic.
Step-by-step explanation:
Given the following data;
Speed = 345 m/s
Wavelength = 500 meters
To find the frequency of the sound wave;
Speed = wavelength * frequency
Frequency = speed/wavelength
Frequency = 345/500
Frequency = 0.69 Hz
Therefore, the sound wave is infrasonic.
Note: Frequency of infrasonic sound = below 20 Hertz.
Frequency of sonic sound = 20 Hz to 20,000 Hertz.
Frequency of ultrasonic sound = above 20,000 Hertz.