A crude approximation of human voice production is to considerthe breathing passages and mouth to be a resonating tube closed at one end. $($See the figure$)$

show answer Correct Answer $50\%$ Part $($a$)$ What is the fundamental frequency, in hertz, of a voice if the tube is $0\mathrm{.}285-$m long, taking air temperature to be $37\mathrm{.}0\backslash$deg C$?$

f$1=310\mathrm{.}26$

f$1=310\mathrm{.}3$

$$ Correct!

show answer Incorrect Answer $50\%$ Part $($b$)$ What would this frequency become, in hertz, if the person replaced the air with helium? Assume the same temperature dependence for the speed of sound in helium as for air, and that the speed of sound in Helium is $965$ m$/$s at $0\backslash$deg C$.$