Answer:
The frecuency is 400 Hz.
Step-by-step explanation:
In a periodic wave the wavelength is the physical distance between two points from which the wave repeats itself. It is named by (λ). That is, the wavelength is the minimum distance between two points on the wave that are in the same state of vibration.
Frequency is represented by the letter f, and is the number of vibrations that occur in a unit of time. That is, how many ridges or valleys are repeated in a unit of time.
The propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave's disturbance propagates along its displacement. Relate the wavelength (λ) and the frequency (f) inversely proportional using the following equation: v = f * λ.
In this case:
Replacing:
340 m/s= f* 0.85 m
Solving:
f= 400 Hz
The frecuency is 400 Hz.