Passage V
Viscous fluid flow occurs when various parts of a fluid interact with each other to produce forces that inhibit flow and generate heat. Students performed 3 studies of viscous fluid flow using the experimental setup shown in Figure 1 below.
In each trial of the studies, the students sent a fluid through a tube such that the fluid completely filled the tube. The fluid had a viscosity η; the tube had a radius R and was fitted with 2 pressure gauges, Gauge G and Gauge H, that were a distance D apart. The pressure of the fluid at Gauge G minus the pressure of the fluid at Gauge H always equaled 5 kilopascals. (A kilopascal, kPa, is a unit of pressure, which is defined as force per unit area.) Using a flow meter, the students measured the fluid’s flow rate through the tube, F, in milliliters per second (mL/sec).
Study 1
The students measured F for various fluids, each having a different η, that flowed, one at a time, through a tube having an R of 5.00 mm and a D of 1.00 m (see Table 1).
Study 2
The students measured F for a fluid having an η of 1.0 × 10−3 Pa·sec that flowed through each of various tubes having the same D, 1.00 m, but different R (see Table 2).
Study 3
The students measured F for a fluid having an η of 1.0 × 10−3 Pa·sec that flowed through each of various tubes having the same R, 5.00 mm, but different D (see Table 3).
27. Suppose that a sixth trial had been performed in Study 1 for which the fluid’s flow rate had equaled 920 mL/sec. In that trial, the viscosity of the fluid would most likely have been:
Your Answer is
Correct Answer is B
Explanation
The flow rate corresponds to F in Table 1. When the value is 920, it should be between 615 and 1230, that is, the viscosity is between 1 and 2