Consider a thin square plate floating on a viscous liquid in a large tank. The height h of the liquid in the tank is much less than the width of the tank. The floating plate is pulled horizontally with a constant velocity u0. Which of the following statements is (are) true?
Viscous force is given by F=−ηAdvdy since h is very small, so magnitude of viscous force is given by
F=ηA△v△y
∴F=ηAu0h (Because v=uo and y = height of fluid (h))
⇒F∝η,F∝u0;
F∝1h,F∝A
Since plate is moving with constant velocity, same force must be acting on the floor.
So Option (A), (C) and (D) are correct