Answer:
Say the full question I can't understand what it is
A. Forced vibrations, such as those between a tuning fork and a large cabinet surface, result in a much lower sound than was produced by the original vibrating body.
λ=v/f
λ-wavelength
v-speed
f-frequency
we have the wavelength(6.2 x 10^-6meters) and we use the speed of light which is equal to 3*10^8m/s
6.2*10^-6m=3*10^8m/s/f
f=(3*10^8m/s)/(6.2*10^-6)≈0.48*10^14Hz
