Determine the length of a wind instrument, assuming that it is modeled as a closed tube and that the lowest sound that it can play has a frequency of 69 Hz. The speed of sound in air is 343 m/s.

length = 1.24m

Explanation:

velocity = frequency x wavelength

wavelength = velocity/frequency

w = 343/69 =4.97m

length = wavelength/4

length =4.97/4 =1.24m

a and b sometimes have a positive value

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.