Speed increases:
* Conservation of mass: The same amount of fluid must pass through any point in the pipe per unit time. If the pipe narrows, the fluid has to move faster to maintain this constant flow rate. Imagine a river narrowing – the water speeds up to fit through the smaller space.
* Continuity equation: This equation mathematically describes the relationship between the flow rate, cross-sectional area, and fluid velocity. It states that the product of the cross-sectional area and the fluid velocity is constant. So, if the area decreases, the velocity must increase.
Pressure decreases:
* Bernoulli's principle: This principle states that as the speed of a fluid increases, its pressure decreases. This is because the kinetic energy (energy of motion) of the fluid increases, taking energy away from the potential energy (energy stored due to pressure).
* Venturi effect: This effect is a practical demonstration of Bernoulli's principle. It shows that when a fluid flows through a constricted section of a pipe, the pressure drops.
In summary:
* Speed increases: The fluid accelerates to maintain the same flow rate through the narrower space.
* Pressure decreases: The increased speed leads to a decrease in pressure due to the conservation of energy.
Important Note: This is a simplified explanation. Real-world situations can be more complex, with factors like friction and viscosity also influencing the pressure and speed changes.
