Optimal Pressure for Firehose: Achieving a 20m Spray Height | Expert Tips

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To achieve a spray height of 20 meters with a firehose, the necessary gauge pressure in the water mains can be calculated using the equation that incorporates density, gravity, and height. Given the density of water as 1000 kg/m³, the required pressure is approximately 19,600 Pa, based on the formula that relates pressure to height. Additionally, applying Bernoulli's principle is essential to determine the velocity of water flow needed to reach this height. The atmospheric pressure outside the hose must also be considered, which is approximately 101,300 Pa. Understanding these calculations is crucial for optimizing firehose performance.
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help//// on pressure... !

Homework Statement

What gauge pressure in the water mains is necessary if a firehose is to spray water to a height of 20 ?



Homework Equations


Pressure = density * gravity * chanfe of height


The Attempt at a Solution



density of the water is 100 kg/m^3
so will the solution be:
100 (kg.^3) * 9.8 (m/s^2)* 20m
=19600 pa?
 
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To determine the gauge pressure inside a hose pipe you have to apply Bernoulli's principle. Inside the pipe the pressure is P and velocity of flow of water is zero. Outside the pipe pressure is ane atmosphere
= 1.013*10^5 pa. Find the velocity of projection of anybody to reach the height h.Use the equation P + 0 = 1.013x10^5 + 1/2xdensity waterxv^2. Density water is 1000kg/m^3
 

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