Final answer:
As water flows through a hose, it experiences resistance that can cause a pressure drop, especially during heavy use. The Bernoulli effect explains how water can still exit the nozzle vigorously by a transformation from potential energy to kinetic energy, despite pressure being less than atmospheric pressure.
Step-by-step explanation:
As water flows through a hose, it experiences resistance against the inside walls of the hose, which results in a loss of pressure known as a pressure drop. This can be particularly noticeable during times of heavy use, such as on hot summer days, when many homes draw water from the same water main. This scenario illustrates the principles of flow and resistance within fluid dynamics.
The decrease in water pressure as it flows through a system can be explained by several factors, including the Bernoulli effect. According to the Bernoulli principle, as the speed of a fluid increases, the pressure within the fluid decreases.
This principle helps explain how water can exit a hose nozzle with significant velocity, even when the pressure inside the nozzle is lower than atmospheric pressure. In terms of energy, as water accelerates through the nozzle, potential energy (pressure) is converted into kinetic energy (motion), allowing the water to emerge against the opposing atmospheric pressure.
A real-world example of this principle occurs when water supply to a house drops during periods of heavy neighborhood use. Even though the pressure at the nozzle may be less than atmospheric pressure, the flow of water can still continue due to the conversions between pressure and kinetic energy described by Bernoulli's principle.