Skip to content
Login Register

#hydrodynamics

2 public questions tagged with this topic.

Viscosity, Stokes' Law and Reynolds Number

A tank has a hole 0.9m below the water surface, open to the atmosphere. What is the efflux speed? (Take g\=10m/s2)

Torricelli’s law: v = 2gh. g = 10m/s2, h = 0.9m. v = 2×10×0.9 = 18≈4.24m/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 4.2 m/s. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

View Details
Bernoulli's Theorem and Applications

Water (ρ\=1000kg/m3) flows horizontally at 4m/s with pressure 1.6×105Pa. If the speed increases to 7m/s, what is the new

Bernoulli’s equation: P1+12ρv12 = P2+12ρv22. P1 = 1.6×105Pa, v1 = 4m/s, v2 = 7m/s, ρ = 1000kg/m3. P2 = 1.6×105+12×1000(16−49) = 1.6×105−16500 = 1.435×105Pa. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 1.435 × 10⁵ Pa. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.

View Details