12 



v^TO Maximum value of Vc 



v„ Maximum value of v 



X Equal to pc/am 



z Deflection of the plate normal to its initial plane; z refers in 



analytical work to an element, but in deflection formulas to the 

 center, where it replaces z^ 



Zj Displacement of a plane baffle 



z^ Value of z at the center 



z„ Value of z due to static pressure 



Zj Central z at the elastic limit 



z, Normal velocity of a liquid surface 



z„ Maximum of z at the center, before unloading 



Zi Value of z^ calculated with disregard of the elastic range 



Zp Normal velocity of a point on the plate 



a A constant in the formula for an exponential pressure wave, p- = p^ 



H 2n times frequency 



or Pi Density of a liquid 



p^ Density of material composing the plate 



a Yield stress 



(t> Net force per unit area on the plate due to stresses in it and to 

 hydrostatic pressure on its two faces 



* Effective force due to <i>, Equation [31b] 



Note:- In all cases, the word "diaphragm" may be substituted for the word 

 "plate." 



