Final answer:
It is true that water flows through a pipe contraction, with the flow speed increasing as the cross-sectional area decreases. This is explained by the conservation of mass and the equation of continuity, and it is exemplified by the Venturi effect.
Step-by-step explanation:
The question at hand deals with the behavior of water (or any incompressible fluid) as it flows through a pipe that narrows or has a contraction. According to principles in fluid dynamics, particularly the conservation of mass and the equation of continuity, it is true that water flows through pipe contractions.
When water transitions from a wider pipe to a narrower one, the cross-sectional area decreases. Because the amount of water (or mass) per unit time that enters the contraction must equal the amount that leaves, the water must increase its velocity to pass through the smaller cross-sectional area. This phenomenon is governed by the equation of continuity, which states that the product of the cross-sectional area (A) and the velocity (V) of the fluid flow at any point is constant (AV = constant). Therefore, if A decreases, V must increase.
An example of this effect is observed with the Venturi effect, where a fluid's velocity must increase as it passes through a constricted section of pipe, resulting in a corresponding decrease in pressure (this can be calculated using the Bernoulli's equation). In practical applications, this principle is utilized in devices such as the Venturi meter, which measures fluid flow rates by observing changes in pressure.