The upper limit of the frequency of wave oscillations perceived by the human ear decreases with age.

The upper limit of the frequency of wave oscillations perceived by the human ear decreases with age. For children, it is 22 kHz, and for the elderly, 10 kHz. The speed of sound in air is 340 m / s. Sound with a wavelength of 17mm.

To solve the problem, we will use the following formula:
wavelength = speed / frequency;
Let’s write it down by the formula:
l = v / V;
Let’s write down the data that we have:
l = 20 mm = 20 * 10 ^ (- 3) m;
v = 340 m / s;
Now let’s find the frequency with this data, using the formula:
V = v / l;
Let’s substitute the values into the formula:
V = 340/20 * 10 ^ (- 3);
V = 17 kHz.
Answer: V = 17 kHz.