Answer:
308 m/s
Explanation:
In a closed tube, the length of the tube (L) is related to the wavelength of the standing wave ([tex]\lambda[/tex]) by the relationship
[tex]L=\frac{1}{4}\lambda[/tex]
In this problem, the length of the tube is L=20 cm=0.20 m, so we can find the wavelength of the standing wave:
[tex]\lambda=4L=4 \cdot 0.20 m=0.80 m[/tex]
And no we can find the speed of the sound wave by using the following equation:
[tex]c=\lambda f[/tex]
where [tex]f=385 s^{-1}[/tex] is the frequency of the wave. So, we find
[tex]c=(0.80 m)(385 s^{-1})=308 m/s[/tex]
f = frequency of the tuning fork = 385 Hz
L = length of the closed tube = 20 cm = 0.20 m
d = diameter of the closed tube = 4 cm = 0.04 m
v = speed of the sound = ?
for closed tube , fundamental frequency is given as
f = v/(4L)
rearranging the equation
v = 4 fL
inserting the values
v = 4 x 385 x 0.20
v = 308 m/s
hence the speed of sound comes out to be 308 m/s
