find the dimensitions of coefficient of viscocity and its SI unit .

According to Stoke's Law, a body of radius r moving with velocity v through a medium of coefficient of viscosity η experiences a viscous force given by:

F = 6πηrv

η = F / (6πrv…… …… ……… …...(i)

Now, dimension of force (F)  =  [M1 L1 T-2]

dimensions of radius (r) = [L1]

dimensions of velocity (v) = [L1 T-1]

6π is a dimensionless factor

therefore, dimensions of coefficient of viscosity (η) = [M1 L1 T-2] / [L1] [L1 T-1]

………  …………………  ……………………  ....... ...........= [M1 L-1 T-1]

From the dimensional formula, the SI unit of coefficient of viscosity (η) is  kg m-1 s-1

  • 48

thx Ghazia

  • -4

MLT-1 and SI unit is N/m sec2

  • -4
What are you looking for?