Question

In a movie, Tarzan evades his captors by hiding under water for many minutes while breathing through a long, thin reed. Assume that the maximum pressure difference his lungs can manage and still breathe is -73 mm-Hg. 1 mm-Hg = 133 N/m2.
Determine the maximum distance below the water surface, at which Tarzan could breathe with the reed.

Answer 1

Answer: 0.98m

Explanation:

P = -74 mm Hg = 9605 Pa = 9709N/m^2

= 9605 kg m/s^2/m^2

density of water: rho = 1 g/cc = 1 (10^-3 kg)/(10^-2 m)^-3 = 1000 kg/m^3

Pressure equation: P = rho g h

h = P/(rho g)

h = (9605 kg/m/s^2) / (1000 kg/m^3) / (9.8 m/s^2)

h = 0.98 m

0.98m is the maximum depth he could have been.