Question

(c)
The figure shows the snapshot of a soun
certain instant
the snapshot of a sound wave in a certain medium at a certain instant


(i) What is the amplitude of the wave?
(ii) If the velocity of the wave is 4m s 1, calculate the wavelength of the wave
if its frequency is 20 Hz.
(iii) If a wave of same type but with higher frequency is passed in the given
medium, will the speed of the wave increase, decrease or remain the same?​

Answer 1

Answers for questions are given below-

(i) Amplitude refers to vertical distance between peak and X axis. It can also be defined as amount of displacement of particle in a medium from its original or resting position.

(ii) Wavelength of a wave is directly proportional to velocity and inversely proportional to frequency.

The equation will be -

Wavelength = velocity/frequency

Velocity given in question is 4 m/s and frequency of wave is 20 Hz.

Wavelength = 4/20

Wavelength = 0.2 m

(iii) Changing the wave frequency will have no effect on wave speed. This is because increase in frequency inversely effects wavelength.

Hence, according to the formula mentioned above, speed will remain constant irrespective of change in wave frequency.