Sound Waves

Two musical notes of the same pitch and same loudness are played on two different instruments Their wave patterns are as shown in Fig. $$7.21$$
A sound wave of wave length 40 em travels in air. If the difference between the maximum and minimum pressures at a given point is $$2.0 \times 10^{-3} N/m^2$$. The amplitude of vibration of the particles of the medium isi $$10^{-x} N/m^2$$.The bulk modulus of air is $$1.4 \times 10^5 N/m^2$$. Find $$x$$.
A wave of frequency 500 Hz has a phase velocity of 360 m/s. The phase difference between the two displacements at a certain point in a time interval of 10$$^{-3}$$ seconds will be how much?
When we clap our hands, the sound produced is best described by
[Here p denotes the change in pressure from the equilibrium value]
The figure given below shows the images of sound waves. Look at them and answer the following questions. Which two sounds were produced by the same instrument?