Question

With what terminal velocity will an air bubble 0.4 mm in diameter rise in a liquid of viscosity 0.1 Ns/m2
and specific gravity 0.9? Density of air is 1.29 kg/m3
.
[Ans. - 0.782 × 10-3 m/s, The negative sign indicates that the bubble rises up

Answer 1

Explanation:

Given With what terminal velocity will an air bubble 0.4 mm in diameter rise in a liquid of viscosity 0.1 Ns/m2 and specific gravity 0.9?  Density of air is 1.29 kg/m3

• We need to find the terminal velocity.  
• So terminal velocity V t = 2/9 r^2 (ρ – σ) g / ƞ
• So r = d/2 = 0.4 / 2 = 0.2 x 10^-3 m
• So σ = 0.9 x 10^3 kg / m^3
• So ρ = 1.293 kg/m^3
• Or ƞ = 0.1 N – S / m^2
• Or g = 9.8 m/s^2
• So V t = 2/9 (0.2 x 10^-3)^2 (1.293 – 0.9 x 10^3) 9.8 / 0.1
• So Vt = 2/9 (0.04 x 10^-6 x – 88073286) / 0.1
•        = - 704.586288 / 0.9 x 10^-6 / 0.9
•       = 782.8 x 10^-6
•     = 0.782 x 10^-3 m / s

Reference link will be

https://brainly.in/question/17362017