By sucking through a straw, a student can reduce the pressure in his lungs to 745 mm of Hg (. density .=13.6 g / cm 3). Using the straw, he can drink water from a glass upto a maximum depth of cm.

Question

By sucking through a straw, a student can reduce the pressure in his lungs to 745 mm of Hg (. density .=13.6 g / cm 3). Using the straw, he can drink water from a glass upto a maximum depth of cm. (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

Pressure-difference between lungs and atmosphere

= 760 mm - 745 mm

= 15 mm

= 1.5 c m

of

H g

Maintaining this pressure difference, let the student drink water upto a depth of

h_{w}

.

∴ h_{w} ρ_{w} g = h_{H g} ρ_{H g} g

∴ h_{w} \times 1 = 1.5 \times 13.6

∴ h_{w} = 20.4 c m

i.e., one can draw from a depth of

20.4 c m

of water

Q. By sucking through a straw, a student can reduce the pressure in his lungs to 745mm of Hg ( density =13.6g/cm3). Using the straw, he can drink water from a glass upto a maximum depth of ________cm.

Pressure-difference between lungs and atmosphere =760mm−745mm =15mm =1.5cm of Hg Maintaining this pressure difference, let the student drink water upto a depth of hw​. ∴hw​ρw​g=hHg​ρHg​g ∴hw​×1=1.5×13.6 ∴hw​=20.4cm i.e., one can draw from a depth of 20.4cm of water

Q. By sucking through a straw, a student can reduce the pressure in his lungs to $745 mm$ of $H g$ $($ density $= 13.6 g / c m^{3})$ . Using the straw, he can drink water from a glass upto a maximum depth of ________ $c m$ .