A solid cube with a side length of 0.4 ft and a weight of 110 lb slides down a smooth surface that is inclined at 45° from the horizontal (Figure P2.20). The block slides on a film of oil with a...

A solid cube with a side length of 0.4 ft and a weight of 110 lb slides down a smooth surface that is inclined at 45° from the horizontal (Figure P2.20). The block slides on a film of oil with a viscosity of 1.85 X
 lb-s/f . If the velocity of the block is 1.2 ft/s, determine the thickness of the oil film assuming a linear velocity distribution in the film.

Q21

Two fixed plates are set at a distance of 12 mm apart. A large, movable thin plate is located between the two fixed plates a distance of 4 mm from the lower plate and 8 mm from the upper plate as shown in Figure P2.21. The space between the upper fixed plate and the movable plate is filled with a fluid with a dynamic viscosity of0.03
 • The other space between the lower fixed plate and the movable one is filled with another fluid with a dynamic viscosity of 0.015
 . Determine the magnitude and direction of the shear stress that act on the fixed places when the speed of the movable plate is 5 m/s. Assume linear velocity distribution in the two oil fields and neglect the thickness of the two places.

Q22.

A plate measuring 20 cm X 20 cm is pulled horizontally through SAEl0 oil at v = 0.15 m/s as shown in Figure P2.22. The oil temperature is 40°C. Find the force F.

Q23.

The place in Problem 2.22 is moved with a velocicy of 0.15 m/s to the righr bur the top and bottom places are moved ro the lefr ar 0.10 m/s, as shown in Figure P2.23. Find the force F.

Problem 2.22

A plate measuring 20 cm X 20 cm is pulled horizontally through SAEl0 oil at v = 0.15 m/s as shown in Figure P2.22. The oil temperature is 40°C. Find the force F.