Question

A uniform narrow tube 1.90 m long is open at both ends. It resonates at two successive harmonics of frequencies 280 Hz and 294 Hz.(a) What is the fundamental frequency?_____Hz(b) What is the speed of sound in the gas in the tube?________ m/s

Answer 1

Answer:

a)14Hz

b)26.6m/s

Explanation:

a)we were given

the first harmonics frequencies as 280 Hz

The second harmonic frequency as 294 Hz.

The fundamental frequency is equal to the gap which means the distance that exist between the harmonics, then

the fundamental frequency=(294 - 280 = 10 Hz)

= 14Hz

b) We know the frequency and the wavelength of the sound wave (

We were told that the wavelength must be twice the length of the tube then, velocity can be calculated as

And fundamental frequency= 14Hz, and distance of 1.90 m then

v = f*2L = (14Hz)*2*(1.90 m) = 26.6m/s

Therefore, the speed of sound in the gas in the tubes is 26.6m/s