You can squirt water a considerably greater distance by placing your thumb over the end of a garden hose and then releasing, than by leaving it completely uncovered. Explain how this works.
The Correct Answer and Explanation is :
When you place your thumb over the end of a garden hose, you create a situation that affects both the pressure and the velocity of the water flowing through the hose. This phenomenon can be explained using Bernoulli’s principle, which relates the speed of a fluid to its pressure.
How It Works
- Pressure Increase: When you cover the end of the hose with your thumb, you restrict the flow of water. This restriction builds up pressure in the hose because the water continues to be pumped from the source (like a tap or a water tank) while the outlet is blocked. The pressure increases until it exceeds the pressure you are exerting with your thumb.
- Velocity Increase upon Release: When you remove your thumb from the end of the hose, the built-up pressure is suddenly released. The water is forced out of the hose with a much higher velocity than if the end were left open. This is due to the principle of conservation of energy: the potential energy stored in the pressurized water is converted into kinetic energy as it exits the hose.
- Increased Distance: The high velocity of the water as it exits the hose allows it to travel a much greater distance than if the water were flowing freely and continuously. In the case of a completely uncovered hose, the water exits at a lower velocity, which means less kinetic energy and a shorter distance traveled.
Conclusion
In summary, by covering the end of the garden hose, you increase the pressure and subsequently release it, allowing the water to shoot out at a high speed. This results in a greater distance traveled compared to the steady flow from an uncovered hose. This principle is not only applicable in everyday gardening tasks but also illustrates fundamental fluid dynamics concepts that are crucial in various engineering applications.