The power (in watts) used to move air out of the lungs is equalto the air pressure (in N/m2) multiplied by the air flowrate (in m3/s). For quiet breathing (where p = 100N/m2 and flow rate = 100 cm3/s or 1.0 x10-4 m3/s), the power involved = 0.01 W ; forloud singing (where p = 4000 N/m2 and flow rate = 400cm3/s or 4.0 x 104 m3/s), thepower involved = 1.6 W.
In problem P7 (above), we determined that the total powerinvolved in moving the air at a pressure of 4000 N/m2(loud singing) = 1.6 W. The fraction (in %) of this total powerthat is converted into and radiated as sound = _______ %.
