Question

Question 6: There is a 1 mm thick layer of oil between a flat plate of area 0.01 m2
and a big plate. If coefficient of viscosity of oil is 1 poise, then how much force is
required to move the plate with a velocity of 2 cm/s
0.015 N
0.030 N
0.010 N
O none of these
Other:​

Answer 1

Explanation:

Using the relation τ=

A

F

=μ

dy

du

where F = force is required to move the plate

τ = Shear stress

A = Area of plate

μ = coeffecient of viscosity of glycerine

y = gap

u = velocity

10

−2

F

=1×

0.001

0.07

.

Thus F = 0.7 N