Question

The wave length and frequency of a sound wave in a certain medium is 22cm and 1500 Hz respectively. If wavelength is changed to 33 cm. Calculate
(1) velocity of sound (ii) new frequency.
a) 330m/s, 1000Hz
b) 3.3m/s, 100Hz
c) 330cm/sec, 1000Hz
d) 300m/s, 100Hz​

Answer 1

Answer:

The wavelength and frequency of a sound wave in a certain medium are 22cm and 1500 Hz respectively. If the wavelength is changed to 33 cm,

i)  Velocity of the sound = 330m/s

ii)  New frequency = 1000Hz

The answer is option c.   

Explanation:

We have the equation for the velocity of sound as,

$v=\frac{\lambda}{T}$   where ${\lambda}$ is the wavelength and T is the time period of the sound wave.

substituting $\frac{1}{T} = f$ which is the frequency of the sound wave

$v= \lambda\times f$

Given,

$\lambda = 22 cm = 0.22 m$

$f = 1500 Hz$  

v = 0.22$\times$ 1500 = 330 m/s

If  $\lambda$ = 33cm= 0.33m,  

New frequecy, f = $\frac{v}{\lambda}$

after substituting the values,

f = $\frac{330}{0.33} = 1000 Hz$

i)  Velocity of the sound = 330m/s

ii)  New frequency = 1000Hz