A flat plate of area 0.1 m 2 is placed on a flat surface and is separated from it by a film of oil 10-5 m thick whose coefficient of viscosity is 1.5 N sm -2. The force required to cause the plate to slide on the surface at constant speed of 1 mm s -1 is

Question

A flat plate of area 0.1 m 2 is placed on a flat surface and is separated from it by a film of oil 10-5 m thick whose coefficient of viscosity is 1.5 N sm -2. The force required to cause the plate to slide on the surface at constant speed of 1 mm s -1 is (A) 10 N (B) 15 N (C) 20 N (D) 25 N

Tardigrade Admin · Accepted Answer

F=η A (V/l) Substituting values, =1.5 × 0.1 × (1 × 10-3/10-5) =15 N

Q. A flat plate of area $0.1 m^{2}$ is placed on a flat surface and is separated from it by a film of oil $1 0^{- 5} m$ thick whose coefficient of viscosity is $1.5 N s m^{- 2}$ . The force required to cause the plate to slide on the surface at constant speed of $1 mm s^{- 1}$ is

10 N

15 N

20 N

25 N

$F = η A \frac{V}{l}$
Substituting values,
$= 1.5 \times 0.1 \times \frac{1 \times 1 0 ^{- 3}}{1 0 ^{- 5}}$
$= 15 N$

Q. A flat plate of area 0.1m2 is placed on a flat surface and is separated from it by a film of oil 10−5m thick whose coefficient of viscosity is 1.5Nsm−2. The force required to cause the plate to slide on the surface at constant speed of 1mms−1 is