In a falling-ball viscometer, a steel ball 1.6 mm in diameter is allowed to fall freely in a heavy fuel oil having a specific gravity of 0.95. Steel weighs 79 kN/m3. If the ball is observed to fall 250 mm in 10.5 s, calculate the viscosity of the oil.

A cylindrical machine part moves within a surrounding cylinder. The centrelines of the part and the surrounding cylinder are coincident. The cylinder is full of an oil (viscosity 0.25kg/ms) that is not flowing i.e. no pressure gradient is applied. What is the value of the viscous force exerted on the machine part as it moves along the cylinder at a speed of 9m/s? • The machine part is 0.06m long and has a radius of 0.041m. • The ratio of the machine part radius to the cylinder radius is 0.98. • Assume that the flow is dominated by viscous forces. • Give your answer as an absolute value i.e. no negative sign, in Newtons to one decimal place.

The kinematic viscosity of and specific gravity of a liquid are 3.5 x 10-4 m^2 /s and 0.79, respectively. What is the dynamic viscosity of the liquid in N-s/m^2?

A gas whose viscosity is 0.98 centipoise flows through a tube 1.0 mm in diameter and 200 mm long. Find the volume in cubic centimetre of the gas which passes through the tube every 10 secs at a pressure of 2 atm.