The power (in watts) used to move air in or out of the lungs is equal to the pressure (in N/m2) multiplied by the flow rate (In

m3/s). Find the power for:

(a) Quiet breathing (p = 100 cm3/s);

(b) Soft singing (p = 1000 N/mz, flow rate = 100 cm3/s);

(c) Loud singing (p = 4000 N/mZ. flow rate = 400 cm3/s).

(a) 0.0001p W

(b) 0.1 W

(c) 1.6 W

Explanation:

(a) As there's only the flowrate 100 cm3/s (or 0.0001 m3/s), and the pressure is missing here, we shall assume that the pressure is p

The power is p*0.0001 = 0.0001p W

(b) p = 1000N/m2 and flow rate is 100 cm3/s or 0.0001 m3/s. The power shall be then

1000 * 0.0001 = 0.1 W

(c) p = 4000 N/m2 and flow rate = 400 cm3/s (or 0.0004 m3/s). The power shall be

4000 * 0.0004 = 1.6 W