2. when sugar or another substance is dissolved in water, it disappears from view and forms a homogeneous mixture with the water, also called a solution.
if you can’t see the sugar, how can you tell that it is there?

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.