Mechanical Properties of Fluids
Mechanical Properties of Fluids
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See all →- Derive an expression for capillary rise for a liquid having a concave meniscus. Consider a capillary tube of radius r partially immersed into a wetting liquid of density p. Let the capillary rise be h and q be the angle... 1
- Obtain an expression for conservation of mass starting from the equation of continuity. Consider a fluid in steady or streamline flow, that is its density is constant. The velocity of the fluid within a flow tube, while everywhe... 1
- Derive Laplace’s law for spherical membrane of bubble due to surface tension. Answer: For a soap bubble (two surfaces) the excess pressure inside is P_i - P_o = 4T/R ; for a single spherical surface such as a liquid dr... 1
- A steel ball with radius 0.3 mm is falling with velocity of 2 m/s through a tube filled with glycerine. Calculate viscous force acting on the steel ball. [ Given : \(\eta_{\text{glycerine}} = 0.833\) N s/m\(^2\) ] Answer: F ≈ 9.42×10⁻³ N By Stokes’ law, F = 6πη r v . r = 0.3 mm = 3×10⁻⁴ m, v = 2 m/s, η = 0.833 N s/m ² . F = 6 × 3.142 × 0.833 × 3×10⁻⁴ ×... 1
- When a number of droplets coalesce to form a single drop, the total surface area of the drop _____. Answer: A. decreases Answer: (a) decreases When n droplets of radius r join, volume is conserved: 4/3π R³ = n·4/3π r³ , so R = n^(1/3) r . T... 1
- The excess pressure inside a soap bubble of radius 2 cm is (surface tension of soap solution = 0.03 N/m) Answer: C. 6 Pa A soap bubble has two surfaces: Δ P=4T/r=4×0.03/0.02=6 Pa. 1