The maximum flowrate through a control valve with an equal percentage characteristic is 10 m/h. if the valve has a rangeability ratio of 50: 1 and is subjected to a constant differential pressure, calculate the percentage change in flowrate through the valve for valve lifts at 10% intervals. hence show that the valve is indeed equal percentage by finding the change in flowrate from one interval to the next.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?