The length of stereocilia actually vary from 10 to 50 micrometers. Again, assuming that they behave like simple pendula, over what frequency range of sound waves would they resonate. (The actual frequency range of human hearing is 20 Hz - 20,000 Hz, so there certainly must be other mechanisms involved in determining the frequency of these being the pendular model is rather oversimplified.) a. About 70 Hz -160 Hz.
b. About 440 Hz - 1000 Hz.
c. About 20 Hz - 50 Hz.
d. About 0.07 to 0.16 Hz.

the frequency range of sound waves is about 70 Hz - 160 Hz

Hence, Option a)  About 70 Hz -160 Hz is the correct answer

Explanation:

Given the data in the question;

L₁ = 10 micrometers = 0.00001 m

so

T₁ = 2π√(L/g)

g = 9.8 m/s

so we substitute

T₁ = 2π√(0.00001 /9.8) = 0.006347

⇒ f₁ = 1 / T₁  = 1 / 0.006347 = 157.55 ≈ 160 Hz

L₂ = 50 micrometers = 0.00005 m

T₂ = 2π√(L/g)

g = 9.8 m/s

so we substitute

T₂ = 2π√(0.00005 /9.8) = 0.0142

f₂ = 1 / T₂ = 1 / 0.0142 = 70.422 ≈ 70 Hz

Therefore, the frequency range of sound waves is about 70 Hz - 160 Hz

Hence, Option a)  About 70 Hz -160 Hz is the correct answer