A metal block of area 0.10 `m^(2)` is connected to a 0.02 kg mass via a string. The string passes over an ideal pulley (considered massless and frictionless) as shown in figure. A liquid with a flim of thickness 0.15 mm is placed between the plate and the table. When released the plate movees to the right with a constant speed of 0.075 m `s^(-1)`. What is the coefficient of viscosity of the liquid?

Options

A. `3.45 xx 10^(3)Pa-s`
B. `3.45 xx 10^(-2) Pa-s`
C. `3.45 xx 10^(-3) Pa-s`
D. `3.45 xx 10^(2) Pa-s`

Answer

C

Explanation

`F_(V)= eta A (dv)/(dx)`
`mg- F_(v)= ma` constant velocity,
`therefore a=0`
`mg= F_(v)`
`mg= eta A(dv)/(dx)`
`eta= (mg dx)/(Adv)`
`eta= (0.02 xx 10 xx 0.6 xx 10^(-3))/(0.2 xx 0.17)`
`eta= 3.45 xx 10^(-2) Pa-s`