JEE Advanced2020PhysicsMechanical Properties of FluidsActual
When water is filled carefully in a glass, one can fill it to a height h above the rim of the glass due to the surface tension of water. To calculate h just before water starts flowing, model the shape of the water above the rim as a disc of thickness h having semicircular edges, as shown schematically in the figure. When the pressure of water at the bottom of this disc exceeds what can be withstood due to the surfac
Correct answer
0
Step-by-step solution
Pressure at the bottom of disc (= ) pressure due to surface tension ( aligned & g h=T ( 1 R ₁ + 1 R ₂ ) & R ₁ > R ₂ & So 1 R ₁ < 1 R ₂ and R ₂= h / 2 & gh = T [ 1 R ₁ + 1 R ₂ ]= T [0+ 1 ~h / 2 ] & h ^2= 2 ~T g & h = 2 ~T g = 2 0.07 10^3 10 = 14 100 10^4 100 & ~h = 14 ~mm =3.741 aligned )