It may seem that predicting a dynamic process such as the speed of sound should not be in the realm of equilibrium thermodynamics. in general that is correct. in this case, however, we can invoke an important principle, that of separation of time scales, to identify local equilibrium and to estimate the speed of sound in an ideal gas. assume a barrel filled with n moles of ideal gas. one end of the barrel is terminated by the flexible membrane of a loud speaker. the membrane can be driven back and forth at high frequency (let us say 0.266 khz or the middle c of piano). a)- first, we will define the property called stiffness of the gas (or bulk modulus). the relative change in volume due to the vibration of the membrane is given by δv/v. similar to the stiffness of a spring (k=- f/x), the stiffness of the gas is also defined as b = - δp/( δv/v). is stiffness an extensive or an intensive property? why?