A cubical block of side a and density `rho` slides over a fixed inclined plane with constant velocity v. There is a thin film of viscon fluid of thickness t between the plane and the block. Then the coefficeint of viscosity of the film will be

Options

A. `eta=(rhoa g t sin theta)/v`
B. `(rho a g t^(2) sin theta)/v`
C. `v/(rho a g t sin theta)`
D. None of these

Explanation

Viscous force `= mg sin theta`
`:. Eta A v/t =mg sin theta` or `etaa^(2) v/t=a^(3) rhog sin theta`
`eta=(trhog sin theta a)/v`