Question

A plate having an area of 0.6m2 is sliding down the inclined plane at 300 to the horizontal with a velocity of 0.36m/s. There is a cushion of fluid 1.8mm thick between the plane and the plate. Find the viscosity of fluid if the weight of the plate is 280N.

Answer 1

Answer:

To find the viscosity of the fluid, we use the formula

F = \eta\frac{\Delta v}{\Delta x}\times AF=η

Δx

Δv

×A

implying that \eta = F \div\frac{\Delta v}{\Delta x} Aη=F÷

Δx

Δv

A

where F = mgsin30^{o}F=mgsin30

o

mgsin30^{o} \div \frac{\Delta v}{\Delta x}\times Amgsin30

o

÷

Δx

Δv

×A

= 280sin30\div \frac{0.36}{1.8\times10^{-3}}\times0.6=280sin30÷

1.8×10

−3

0.36

×0.6

140 \div 120 = 1.17 (Pa . s)140÷120=1.17(Pa.s)