Answer:
F=989.6 N
Step-by-step explanation:
Given that
Diameter of shaft = 70 mm
Diameter of bearing sleeve =70.2 mm
So clearance h=0.1 mm
Speed V= 400 mm/s
Length of shaft = 250 mm

We know that

μ= 900 x 0.005 Pa-s
μ= 4.5 Pa-s
As we know that
From Newton's law of viscosity ,the shear stress given as follows

We also know that
Force = shear stress x area
Now by putting the values


So force
F= 18,000 x π x 0.07 x 0.25
F=988.6 N