Snorkeling by humans and elephants. When a person snorkels, the lungs are connected directly to the atmosphere through the snorkel tube and thus are at atmospheric pressure. In atmospheres, what is the difference ?p between this internal air pressure and the water pressure against the body if the length of the snorkel tube is (a) 27 cm (standard situation) and (b)3.6 m (probably lethal situation)? In the latter, the pressure difference causes blood vessels on the walls of the lungs to rupture, releasing blood into the lungs.
Explanation / Answer
(a) The pressure difference P between this internal air pressure and the water pressure against the body if the length of the snorkel tube is P = gh Here = density of blood = 1025 kg/m3 g = 9.80 m/s2 h = 27 cm = 0.27 m Then substituting these values in the above formula we get P = (1025 kg/m3)(9.80 m/s2)(0.27 m) = 2712.15 Pa (b) The pressure difference P between this internal air pressure and the water pressure against the body if the length of the snorkel tube is P = gh Here = density of blood = 1025 kg/m3 g = 9.80 m/s2 h = 3.6m Then substituting these values in the above formula we get P = (1025 kg/m3)(9.80 m/s2)(3.6 m) = 36162 Pa The pressure difference P between this internal air pressure and the water pressure against the body if the length of the snorkel tube is P = gh Here = density of blood = 1025 kg/m3 g = 9.80 m/s2 h = 3.6m Then substituting these values in the above formula we get P = (1025 kg/m3)(9.80 m/s2)(3.6 m) = 36162 Pa