Bones have a value of 7.0 rayls for an analog of this quantity. Correcting for differences in an acoustic analog of this quantity, defined as the density times the local speed of sound, is the primary purpose of the middle ear. The quotient of a difference of two of these quantities over a sum of two of these quantities defines the reflection coefficient. This quantity equals “j-omega-L” for an ideal inductor and “one over (*) j-omega-C” for an ideal capacitor. To optimize power transfer, this quantity should be “matched” between transmission lines and loads. For sinusoidal signals, this quantity is defined as a ratio of phasors representing voltage (10[1])and current in an analog of Ohm’s law. For 10 points, name this complex quantity (-5[1])symbolized Z, the AC analog of resistance. ■END■ (10[1])