# Firefighter's Water Stream Strike Height Calculation

• jitto92
In summary, the problem involves a firefighter standing 44.0 m away from a burning building and directing a stream of water from a ground level hose at an angle of 31.2° above the horizontal. The speed of the stream is 40.0 m/s. To find the height at which the stream will strike the building, we can use the equations v(x)=vcos31.2 and v(y)=vsin31.2 to break down the components of the stream's velocity. Using the equation R=(vsin^2(31.2))/g, we can calculate the height of the stream as it hits the building without needing the actual height of the building.
jitto92

## Homework Statement

A firefighter, 44.0 m away from a burning building, directs a stream of water from a ground level fire hose at an angle of 31.2° above the horizontal. If the speed of the stream as it leaves the hose is 40.0 m/s, at what height will the stream of water strike the building?
v=40.0m/s
v(x)=vcos31.2
v(y)=vsin31.2
g=9.81

## Homework Equations

R=(vsin^2(31.2))/g
x(t)=vcos(31.2)

## The Attempt at a Solution

I have tried breaking it down to x and y components but it doesn't make sense if the height of the building and its distance from the firefighter is not given !

jitto92 said:
I have tried breaking it down to x and y components but it doesn't make sense if the height of the building and its distance from the firefighter is not given !
(1) The distance from the firefighter is given.
(2) You don't need the height of the building, just the height of the stream as it hits the building.

## What is a firefighter's water stream strike height calculation?

A firefighter's water stream strike height calculation is a mathematical formula used to determine the maximum height at which water should be directed from a fire hose in order to effectively extinguish a fire.

## Why is it important for firefighters to calculate the water stream strike height?

Calculating the water stream strike height is important because it ensures that water is being directed at the most effective height to reach the base of the fire and extinguish it. Without this calculation, water may not reach the fire and the fire could continue to spread.

## What factors are involved in the calculation of a firefighter's water stream strike height?

The factors involved in the calculation include the type and size of the fire, the type and pressure of the fire hose, and the distance between the fire and the nozzle of the fire hose.

## How is the water stream strike height calculated?

The calculation involves using a formula that takes into account the factors mentioned above. The formula is: (0.0505 x √(GPM x NP))/√(Distance in feet). GPM refers to gallons per minute, NP refers to nozzle pressure, and the distance is measured in feet.

## Can the water stream strike height calculation be used for all types of fires?

The water stream strike height calculation is most effective for structure fires. It may not be as accurate for other types of fires, such as wildfires or industrial fires, as different factors may need to be considered in those situations.

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