Mechanical Properties Of Fluids Question 5

Question 5 - 29 January - Shift 2

A metal block of base area $0.20 m^{2}$ is placed on a table, as shown in figure. A liquid film of thickness $0.25 mm$ is inserted between the block and the table. The block is pushed by a horizontal force of $0.1 N$ and moves with a constant speed. If the viscosity of the liquid is $5.0 \times 10^{-3} Pl$, the speed of block is $\times 10^{-3} m / s$.

Show Answer

Answer: (25)

Solution:

Formula: Stoke’s Law

$|F|=\eta A \frac{\Delta v}{\Delta h}: 0.1=5 \times 10^{-3} \times 0.2 \times \frac{v}{.25 \times 10^{-3}}$

$v=0.025 m / s$ or $v=25 \times 10^{-3} m / s$