Two identical open containers are connected by a completely filled
PHYSICS · Single correct · AP · Physics 1: Algebra-based · Fluids · Fluids
Problem
Two identical open containers are connected by a completely filled, inverted U-shaped tube. After container B is lowered so that its water surface is 0.25 m below that of container A, water steadily flows through the tube from A to B.
Which of the following best explains why the water continues to rise over the highest point of the tube and flow into container B?
(a) Atmospheric pressure is greater on the surface of the lower container, so that larger pressure forces the water through the tube.
(b) The difference in height between the two liquid surfaces creates a hydrostatic pressure difference that pushes the water through the tube.
(c) Once the water in the tube begins to move, its inertia carries it over the crest even though the pressures at the two surfaces are equal.
(d) Adhesive forces between the tube walls and the water (capillary action) draw the liquid up and over the crest.