Question

Water flows between two plates, of which the upper one is stationary and the lower one is moving with a velocity $V$. What will be the velocity of the fluid in contact with the upper plate?

• A. $V$
• B. $\frac{V}{2}$
• C. $2V$
• D. $0$

Answer 1

The correct option is D $0$

Since the upper plate is stationary, according to the no-slip condition, the relative velocity between the plate and the fluid in contact with it must be zero.
Thus, the velocity of the fluid layer in contact with the upper plate is $0$ and of the fluid layer in contact with the lower plate will be $V$.