1. For a plane sound wave traveling in air and has sound pressure level of 10 dB find the acoustic root-mean-square pressure, acoustic root-mean-square particle velocity. acoustic root-mean-square particle density. 2. Calculate the root-mean-square pressure for a plane wave in water with the same particle velocity as the answer to 1. 3. Given that the ambient pressure, density, and absolute temperature of perfect gas. derive an expression for the variation of the sound speed in air with temperature. 4. For a plane sound wave in air of 100 Hz that has a peak aconstic pressure amplitude of 2 Pa find the root-mean-square pressure, intensity, intensity level, peak particle velocity amplitude, sound pressure level. 5. Two harmonic sources produce sound pressure levels of 90 dB and 93 dB. respectively. If the waves are in phase what will the resultant SPL at the observation point? If the two sources generate incoherent noise so that the resultant squared pressure is given by summing the squares of the individual pressures what will the resultant SPL? 6. Suppose that the SPL is 90 dB when one of the machines ceased to operate. Given that it was 95 dB when it was working. What is the SPL of the machine? 7. The noise level measured at a factory when not in operation is 60 dB. We also know that the SPL of the factory is 63 dB when only one machine is in operation. What would be the SPL when an identical machine is added? 8. A harmonic plane wave traveling in the positive a direction interferes with a harmonic plane wave of the same frequency traveling in the negative e-direction. The negative going wave has an amplitude which is one half that of the positive going wave. Derive general expressions for the net pressure amplitude, particle velocity amplitude and complex specific acoustic impedance. Express your results as a function of in terms of the amplitude of the positive going wave assuming that the phase difference between the two waves is zero at z = 0).