Question

Sound waves of wavelength 3cm have a velocity of 336 m/s in air. What. a is their frequency? Can this sound he heard by the human ear?

Answer 1

frequency= 336÷3/100=11200 hertz
Yes human ear can hear this sound as the range is between 20 hz to 20000 hz.

Answer 2

The concept of the question is based on the sound chapter and specifically the frequency - wavelength formula
This formula states
$speed \: of \: sound \: in \: air = v \times lamda$
Where v = frequency of sound
And, lamda is the wavelength.

So as per the question
336 =frequency * 0.03

(now, question is why we took wavelength as 0.03 and not 3. This is because we take the same units. Speed is in m/sec and wavelength in cm. So, we need to change wavelength into m thats why we took 0.03m)

Now, back to question.

Frequency = 336/0.03
Frequency =11200Hz

Yes the sound is audible to human ears.
This is because the range of human hearing is regarded as 20 Hz to 20000Hz
So, the calculated frequency comes under this range hence it is audible to human ear.

Just for Knowledge :- sometimes the babies under the age of 5 years have a different range of hearing. They have the range which ranges between 20 Hz to 25000Hz.

Hope this will be helping you.

WARM REGARDS
Sahil khirwal