58 ANALOGIES 



Acoustical 



MXX + rj,X^ + 77- = Pe^"'X 4.37 



MX + rAX^^ = P^''^' 4.38 



^A 



The steady state solution of equations 4.34, 4.36 and 4.38 are: 

 Electrical 



q = i = = - 4.39 



Te + jwL — 



Mechanical 



Acoustical 



Fe'"'' / 



M 



X = — — =•'— 4.40 



rM+JoiM—;- 



P^ P 



X = — = — 4.41 



ooLa 



The vector electrical impedance is 

 2^ = rE + 

 The vector mechanical impedance is, 



1 



ze = rE + jwL — 4.42 



wLe 



Zm = rM +joim — - 4.43 



coCm 



The vector acoustical impedance is 



za = ta + jo^M ^—- 4.44 



Electrical impedance is the complex quotient of the voltage by the cur- 

 rent. The unit is the abohm. 



Electrical resistance is the real component of the electrical impedance. 

 The unit is the abohm. 



Electrical reactance is the imaginary component of the electrical imped- 

 ance. The unit is the abohm. 



Electrical abohm. An electrical resistance, reactance or impedance is 



