(adsbygoogle = window.adsbygoogle || []).push({}); Help!! Physics Fluids problem

1. The problem statement, all variables and given/known data

Water is forced out of a fire extinguisher by air pressure. How much gauge air pressure in the tank (above atmospheric) is required for the water jet to have a speed of 29.8 m/s when the water level is d=0.515 m below the nozzle?

2. Relevant equations

I tried using bernoulli's equation, p1+ 1/2*p*v1^2 + p*g*y1= p2 + 1/2*p*v2^2 + p*g*y2

I am not sure what variables I am supposed to put in where, as the diagram i am given in the question is that of a tank with a water pipe in the middle of it.

3. The attempt at a solution

I attempted to solve for p2, using p1 as atmospheric pressure, density as the density of water, v1 as 29.8m/s^2, height as 0.515. The rest of the terms on the second half of the equation I thought would cancel because the height would be 0 and I thought the starting velocity is 0. I ended up getting -4.49 x 10^5 Pa...which isn't right...please help!

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Help Physics Fluids problem

**Physics Forums | Science Articles, Homework Help, Discussion**