Question

A gas bubble of diameter 2cm rises at the rate of 2.5mm/sec through a solution of density of 2.25g/cm3. Calculate the coefficient of viscosity of the neglect the density of gas. ​

Answer 1

Explanation:

As gas bubble is moving upward with constant speed so Buoyant force = Viscous drag force

⇒F b

=F

v

⇒(

3

4

πr

3

)ρg=6πηrv

⇒η=

9

2

v

r

2

ρg

Here, r=1cm,

ρ=1.75gcm

−3

,

g=980cms

−2

v=0.35cms

−1

,

η=?

∴η=

9

2

×

0.35

1

2

×1.75×980

=1088.88≈1089poise

Answer 2

Answer:

two numbers are in the ratio of 4:6 if the sum of the two numbers is 340, find the two numbers.

A. 140 and 204

B. 136 and 204

C. 120 and 216

D. 108 and 195