Question

A plate moves at 2 m/s with shearing force of 3.5 N/m2. The distance between the moving plate and fixed plate is 1 mm. Determine the viscosity of the fluid between the plates. 

Answer 1

The shearing force can be expressed in terms of viscosity $\mu$, velocity $v$, and thickness $h$:

$$\tau=\frac{\mu v}{h},\\\space\\ \mu=\frac{\tau h}{v}=1.75·10^{-3}\text{ Pa}·\text s.$$