Force to slide the two surface over each other is given as
[tex]F = \eta A \frac{dv}{dx}[/tex]
as we know that
[tex]F = 5.50 \times 10^{-4} N[/tex]
[tex]A = 6 \times 10^{-4}[/tex]
[tex]\frac{dv}{dx} = \frac{1\times 10^{-2}}{1.50 \times 10^{-3}}[/tex]
now plug in all data in above formula
[tex]5.50 \times 10^{-4} = \eta 6 \times 10^{-4} \frac{1 \times 10^{-4}}{1.50 \times 10^{-3}}[/tex]
[tex]\eta = 0.1375 Pa s[/tex]
This is approximate range of Motor Oil