Question 1.44: It is of interest to compare the sonic velocity for standard...

(a) Table A.1 in Appendix A is used to read the sonic velocity for standard atmosphere at 0ft above sea level as follows:

where the corresponding temperature at 0 ft above sea level is 59^{\circ }F.

(b) The sonic velocity for standard atmosphere and the sonic velocity for water, both at standard sea-level atmospheric pressure, are compared at a common temperatureofabout 59^{\circ }F For 60^{\circ }F,respectively.Thus,the sonic velocity for water at 60^{\circ }F at standard sea-level atmospheric pressure is determined by applying Equation 1.160 c=\sqrt{\frac{dp}{d\rho } } =\sqrt{\frac{E_{\upsilon } }{\rho } } . Table A.2 in Appendix A is used to read the bulk modulus of elasticity, E_{\upsilon } , and the density, ρ for water at standard sea-level atmospheric pressure, at 60^{\circ }F, as follows:

slug:=1lb \frac{sec^{2} }{ft}                  E_{\upsilon water} :=311000\frac{lb}{in^{2} }                  \rho _{water} :=1.938\frac{slug}{ft^{2} }
C_{water} := \sqrt{\frac{E_{\upsilon water}}{\rho _{water}} } =4.807 \times 10^{3} \frac{ft}{sec}                 \frac{C_{water}}{C_{standardatm}} =4.306

hus, the sonic velocity for water is about four times the sonic velocity for standard atmosphere both at standard sea-level atmospheric pressure and at a temperature of about 59^{\circ }F or 60^{\circ }F.