Question

A tuning fork, frequency 385/sec produces resources with a closed tube 20cm long and 4cm in diameter what is the speed of sound?[338m/s]

Answer 1

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

Answer 2

Answer:

308 m/s

Explanation:

In a closed tube, the length of the tube (L) is related to the wavelength of the standing wave ($\lambda$) by the relationship

$L=\frac{1}{4}\lambda$

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:

$\lambda=4L=4 \cdot 0.20 m=0.80 m$

And no we can find the speed of the sound wave by using the following equation:

$c=\lambda f$

where $f=385 s^{-1}$ is the frequency of the wave. So, we find

$c=(0.80 m)(385 s^{-1})=308 m/s$