4. Consider an experiment to determine the viscosity coefficient of a liquid. The liquid fills the space between the two plates, and the distance between the plates is h. The lower plate is stationary and the upper plate, having area A, is pulled to the right with constant velocity, V. You can measure the velocity and the force, F, required to pull the plate. Assume that there are no edge effects. Copyright © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education u=V u = 0 u(y) Moving plate: u = V Viscous fluid x Fixed plate (a) Find an expression for viscosity coefficient in terms of known or measured values. You may assume that the velocity profile of the fluid is as shown in the figure. (b) In an attempt to identify a certain liquid by running this experiment, you find that it requires 0.02375 N of force to pull the plate at a speed of 0.5 m/s. If the gap height is 2 cm and the plate is 1 m long and 0.5 m wide, what liquid might be between the plates? Assume that the experiment takes place at a temperature of 20°C.

Fig: 1