Question

What frequency must a sound wave have in air to have the same wavelength as a 750 Hz sound wave in a platinum bar? Vair = 340 m/s, Vpt = 2800 m/s,

Answer 1

Answer:

f = 91.1 Hz

Explanation:

As we know that it is given here that wavelength of sound in platinum is same as the wavelength of sound in air

so we can use the formula of wavelength in two mediums

$\frac{speed}{frequency} = \frac{speed}{frequency}$

now it is given that

$v_{air} = 340 m/s$

$v_{pt} = 2800 m/s$

frequency of sound in platinum is 750 Hz

now frequency of sound in air = f

now from above formula

$\frac{340}{f} = \frac{2800}{750}$

$f = 91.1 Hz$