20. A vibrating tuning fork sends sound waves into the air surrounding it. During the time in which the tuning fork makes one complete vibration, the emitted wave travels
(A) one wavelength
(B) about 340 meters
(C) a distance directly proportional to the square root of the air density
(D) a distance inversely proportional to the square root of the pressure
(A) one wavelength
(B) about 340 meters
(C) a distance directly proportional to the square root of the air density
(D) a distance inversely proportional to the square root of the pressure