A metal plate of area 0.10 m^(2) is connected to a 0.01 kg mass via a string that passes over an ideal pulley (considered massless and frictionless), A liquid with a film thickness of 0.3 mm is placed between the plate and the table. When released the plate moves to the right with a constant speed of 0.085 ms^(-1). Find the coefficient of viscosity of the liquid.

A metal plate of area 0.10 m^(2) is connected to a 0.01 kg mass via a

1.	A metal plate of area 0.10 m^(2) is connected to a 0.01 kg mass via a string that passes over an ideal pulley (considered massless and frictionless), A liquid with a film thickness of 0.3 mm is placed between the plate and the table. When released the plate moves to the right with a constant speed of 0.085 ms^(-1). Find the coefficient of viscosity of the liquid.
Answer» SOLUTION : Here `A=0.10m^(2),m=0.01kg` `dx=0.3mm=0.3xx10^(-3)m,dv=0.085ms^(-1)` The METAL plate moves towards right du tothe tension T in the string which is equal to the weight of the suspended mass m. ASSUMING thatthe mass m moves with uniform velocity or zero acceleration, then the FORCE of viscosity will be, `F=T=mg=0.01xx9.8` `=9.8xx10^(-2)N` Taking velocity gradient to be uniform, then `eta=(F)/(A).(dx)/(dv)=(9.8xx10^(-2)xx0.3xx10^(-3))/(0.10xx0.085)` `=3.45xx10^(-3)PaS`