2. A plate underneath a previously still semi-infinite volume of fluid at 20°C suddenly starts moving in the positive x-direction at t=0. After a certain amount of time, the velocity of the fluid at a point above the plane will also be non-zero. Will the velocity at this point (x1, y1) at time t1 be larger if the fluid is air or milk? Explain your answer and provide the supporting equations.

Fig: 1