Question

water moves through a horizontal section of pipe with different cross - sectional diameters at points p and q as shown in the figure.
which of the following claims about the volume of water moving through the pipe is correct?
a a greater volume of water passes section q each second when compared to section p.
b a greater volume of water passes p each second when compared to section q
c an equal volume of water passes section p and section q each second.
d the volume of water that passes each section depends on the direction the fluid is flowing.

Explanation:

This problem is about fluid flow in a pipe, specifically the volume flow rate. According to the principle of continuity in fluid mechanics (a concept in Physics, which is a subfield of Natural Science), for an incompressible fluid (like water, assuming ideal conditions here) flowing through a pipe, the volume flow rate (volume per unit time) is constant at all cross - sections. That is, the volume of fluid passing through any section of the pipe per second remains the same. So, an equal volume of water passes through Section P and Section Q each second. Option A is wrong because it says a greater volume passes through Q than P, Option B is wrong as it says a greater volume passes through P than Q, and Option D is incorrect as the volume flow rate doesn't depend on the direction (the continuity equation is about the amount of fluid, not the direction's effect on the volume passing per second in this context).

Answer:

C. An equal volume of water passes Section P and section Q each second.