By sucking through a straw, a student reduces pressure in the lungs to 750 mm of Hg (density of mercury = 13.6 g/cm³). Taking atmospheric pressure as 760 mm of Hg, what is the maximum height of water that can be lifted through the straw?
Options

Question

By sucking through a straw, a student reduces pressure in the lungs to 750 mm of Hg (density of mercury = 13.6 g/cm³). Taking atmospheric pressure as 760 mm of Hg, what is the maximum height of water that can be lifted through the straw?

Options

G1 Physics · Accepted Answer

Step 1: The available pressure difference is ΔP = 760 − 750 = 10 mm of Hg. Step 2: Equate liquid pressure heads: ρHg g(10 mm) = ρwater gh. Step 3: h = (ρHg/ρwater) × 10 mm = 13.6 × 10 mm = 136 mm. Step 4: Convert: h = 13.6 cm. Final answer: 13.6 cm (Option C).